Why this result mattered
Functional tie
The principal comparison placed Qwen 3.8 and Claude under concealed A/B labels.
Both answers place Fathom on the same material path: treat January 2, 2023 as the negligence pivot, regard contract and fraud as timely on the supplied record, and obtain targeted evidence of when Quarry Ridge received or learned the report’s findings before moving. Both recommend a negligence limitations motion only if discovery occurred by January 1, 2023.
Fast audit
Open the underlying record
These links open all four answers, the principal blind judgment, original prompt, and sealed key.
Prompt and sealed key
The key is an audit reference. It was not shown to the contestant systems and did not determine the comparative verdict.
Read the original matter prompt
Question 63: The Migration Claim Across Five Exhibits
Your role
You represent Fathom Data Services, which has been sued by Quarry Ridge Supply over a failed records migration. Build the limitations analysis from the five exhibits, calculate the deadline range, and identify the one missing fact that must be obtained before Fathom decides whether to move for judgment on limitations.
Governing law
Assume the following limitations rules apply:
A professional-negligence claim must be filed within two years after the claimant discovered, or through reasonable diligence should have discovered, both an actual injury and a factual connection between the injury and the defendant's work.
Discovery does not require final quantification, certainty, or knowledge of a legal theory. Mere unsupported suspicion of a problem, without facts connecting actual injury to the defendant, is insufficient.
A reliable technical report identifying data loss and attributing it to the defendant ordinarily starts the discovery period when the claimant receives the report.
A contract claim must be filed within four years after breach, regardless of later discovery.
A fraud claim must be filed within three years after discovery of facts constituting the alleged fraud. Knowledge of contradictory system results and the defendant's contrary assurance may trigger inquiry, but the claimant must possess facts indicating falsity rather than mere error.
A written tolling agreement suspends an unexpired limitations period for the exact number of calendar days stated. It does not revive a period that expired before tolling began.
When days are added under a tolling agreement, the adjusted deadline is the original deadline plus the suspended days. Filing on the adjusted deadline is timely.
The defendant bears the initial burden to establish apparent untimeliness. The claimant bears the burden of proving delayed discovery or tolling once the ordinary period appears to have expired.
Exhibits
Exhibit 1, September 14, 2022 finance email
Quarry Ridge's controller wrote:
“The old and new receivable totals do not match. This may be our import setup or Fathom's mapping. We do not yet know whether records are actually gone.”
Exhibit 2, technical report dated December 20, 2022
An outside forensic accountant concluded that 11,400 historical invoice lines had been overwritten and that Fathom's migration map caused the loss. The report quantified probable collection loss at $2.4 million. The copy produced in discovery contains no transmittal email, download log, or received stamp.
Exhibit 3, January 10, 2023 board minutes
The minutes state:
“The board reviewed the forensic report attributing the overwrite to Fathom and authorized a claim.”
Exhibit 4, tolling agreement
Fathom and Quarry Ridge agreed that every limitations period still unexpired on November 1, 2024 would be suspended for 120 calendar days. The agreement expired February 28, 2025 and expressly did not revive expired claims.
Exhibit 5, complaint
Quarry Ridge filed professional-negligence, contract, and fraud claims on May 2, 2025. It alleges the migration breach occurred on August 15, 2021 and that Fathom repeatedly said the mismatch was temporary until the forensic report established permanent loss.
Fathom's production contains the report body but not the forensic accountant's delivery email or portal-access metadata. Quarry Ridge's counsel states that delivery occurred “after the holidays,” but has not supplied a date.
Assignment
Analyze:
- Whether the September 14 email starts discovery under the supplied standard.
- The earliest and latest discovery dates supported by Exhibits 2 and 3.
- The two-year professional-negligence deadline at both ends of that range.
- The effect of the 120-day tolling agreement and whether it began before either possible deadline expired.
- The exact report-delivery date at which the May 2, 2025 complaint changes from untimely to timely.
- Timeliness of the contract claim from the August 15, 2021 breach.
- Timeliness of the fraud claim on the present record.
- The specific missing evidence to demand.
- Whether Fathom should move now, seek targeted discovery, or take another concrete course.
Read the sealed key
Q63 key (Migration Limitations)
- The September 14 email likely does not start discovery: it identifies a mismatch but expressly leaves actual loss and causal source unresolved between Quarry Ridge and Fathom. Under the supplied rule, that is supported suspicion of a problem but not yet facts connecting injury to Fathom. Missed: the defense selects a date whose own text defeats the required knowledge.
- The report date, December 20, 2022, is the earliest possible receipt date; the January 10, 2023 board minutes prove receipt no later than January 10. Discovery therefore falls within that 21-day range, but the date printed on the report does not prove delivery. Missed: document creation is silently equated with claimant receipt.
- Without tolling, the negligence deadline ranges from December 20, 2024 to January 10, 2025. Both periods were unexpired when tolling began November 1, 2024, so the agreement adds 120 days. Adjusted deadlines range from April 19, 2025 to May 10, 2025. Missed: tolling is ignored or applied to revive rather than suspend.
- The May 2 complaint is timely only if discovery occurred on or after January 2, 2023. Receipt before January 2 produces an adjusted deadline before May 2; receipt on January 2 produces a May 2 deadline. Missed: the motion is filed without identifying the exact dispositive threshold.
- Demand the forensic accountant's transmittal email, portal access and download logs, billing entry, cover letter, Quarry Ridge inbox metadata, and witnesses who sent or received the report. The phrase “after the holidays” is not a date. Missed: Fathom asks for judgment on an evidentiary gap it bears the initial burden to frame.
- The contract claim accrued August 15, 2021. Its ordinary four-year deadline was August 15, 2025; tolling began while it was unexpired and extends it 120 days to December 13, 2025. The May 2 filing is timely. Missed: a negligence limitation is applied to contract.
- The fraud claim is timely on either report-receipt endpoint because its three-year discovery period, even before adding tolling, extends beyond May 2, 2025. Earlier triggering based on Fathom's assurances cannot be established from the supplied exhibits without facts showing Quarry Ridge knew falsity. Missed: the entire action is described as time-barred.
- Seek expedited targeted discovery on delivery and then move only against professional negligence if receipt was before January 2. Do not seek judgment on contract or fraud from this record. Missed: an overbroad motion loses the one potentially dispositive defense.
Direct judge report
The report below is preserved from the Qwen 3.8 versus Claude verdict record.
Read the preserved judge report
Basis. Both answers place Fathom on the same material path: treat January 2, 2023 as the negligence pivot, regard contract and fraud as timely on the supplied record, and obtain targeted evidence of when Quarry Ridge received or learned the report’s findings before moving. Both recommend a negligence limitations motion only if discovery occurred by January 1, 2023.
[A] rejected: “before or after January 2” as equivalent pivot wording — internally inconsistent with its repeated correct conclusion that receipt on January 2 is timely.
[B] rejected: fraud discovery had to predate May 2, 2022 for untimeliness — tolling arithmetic contradicts that cutoff.
[B] rejected: “after the holidays” ordinarily means on or after January 2 — record does not define that phrase.
[B] rejected: possible interim reports, oral briefings, tort-only damages, pleading defects, punitive exposure, and contractual limitations — record lacks those facts and governing rules.
Failed candidate: B’s broader discovery requests — concrete consequence failed; both obtain the dispositive discovery date, and no different client outcome is established.
Failed candidate: B’s incorrect fraud cutoff — different conduct failed; both conclude fraud is timely and advise against a limitations motion on the present record.
Failed candidate: B’s additional merits and damages strategy — record support failed; the supplied materials do not establish those defenses or exposures.
Failed candidate: A’s isolated pivot phrasing — different conduct failed; its calculations and recommendation consistently apply the correct on-or-after-January-2 rule.
Hard stop. The required sentence cannot be completed with a concrete, record-supported difference in client outcome.
All six pairings
Every pair of the four model answers was judged independently under the same evaluation instrument.
Open the six head-to-head results
| Pairing | Result | Why it mattered | Record |
|---|---|---|---|
| Qwen 3.8 27B vs Claude Opus 5 | Functional tie | Both answers place Fathom on the same material path: treat January 2, 2023 as the negligence pivot, regard contract and fraud as timely on the supplied record, and obtain targeted evidence of when Quarry Ridge received or learned the report’s findings before moving. | Judge record |
| Qwen 3.8 27B vs DeepSeek V4-Flash-0731 | Functional tie | Both answers conclude that the September email does not trigger discovery, calculate the same December 20, 2022–January 10, 2023 range and January 2, 2023 pivot, and direct Fathom to obtain the report-receipt date before moving only against professional negligence. | Judge record |
| Qwen 3.8 27B vs Qwen 3.5 27B | Functional tie | Both answers place Fathom on the same material path: treat January 2, 2023 as the timeliness pivot, regard contract and fraud as timely on the present record, and obtain targeted evidence of report receipt before moving on professional-negligence limitations. | Judge record |
| DeepSeek V4-Flash-0731 vs Claude Opus 5 | Functional tie | Both answers direct Fathom to preserve the defense, defer a limitations motion, and obtain targeted evidence establishing when Quarry Ridge received or learned the report’s findings. | Judge record |
| DeepSeek V4-Flash-0731 vs Qwen 3.5 27B | Functional tie | Both answers direct Fathom to preserve the defense, obtain the report’s exact receipt date, and move against professional negligence only if receipt preceded January 2, 2023. | Judge record |
| Qwen 3.5 27B vs Claude Opus 5 | Functional tie | Both answers place Fathom on the same materially correct path: the September email does not trigger discovery, January 2, 2023 is the negligence pivot date, and Fathom should obtain the report-delivery date before moving. | Judge record |
Rejected-point diagnostic
Judge-attributed rejected points for this matter across all six pairings:
| Qwen 3.8 27B | 1 |
|---|---|
| DeepSeek V4-Flash-0731 | 0 |
| Claude Opus 5 | 6 |
| Qwen 3.5 27B | 11 |
This is a review-burden diagnostic, not a universal hallucination measure.