The Adjuster's Deadline: Negative Corpus and Moved Evidence
An 11 m x 8 m detached three-car garage with a finished apartment above shares a lightweight wood truss floor-ceiling assembly (2x4 webs, gusset plates). Fire reported 04:10; first unit on scene 04:19; knockdown 05:05. You arrive at 09:30 the next morning. Before your arrival the engine company pulled 12 m of apartment ceiling, the homeowner's brother moved a sofa and the apartment's portable space heater (cord and plug attached) to the driveway, and the homeowner hosed down the garage floor. The heater had been against the rear wall. A neighbor states she saw fire 'low down at the front of the garage' at 04:05. The receptacle serving the heater was removed by fire personnel and placed in an unlabeled plastic bag with other parts. The insurer's adjuster says: 'Nothing else makes sense - write it up as the space heater; I need it by Friday.'
1. Resolve the conflict between the neighbor's observation and the heater's location, and explain how the truss assembly changes the origin analysis.
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The conflict is real and must be confronted, not averaged. A witness placing fire low at the front at 04:05, five minutes before the alarm, is evidence of an origin at the front. The heater at the rear is a candidate appliance, not a candidate origin. Either the witness is describing flames already through a front opening from a rear origin, or the origin is genuinely at the front and the heater is irrelevant.
Testable discriminators: burn patterns at the front opening (a fire venting from the rear produces a plume-driven pattern high and a distinct inflow pattern low, not a localized low-level origin), debris removal and floor protection at both locations, and interviews establishing sightline and distance.
Truss effect: a lightweight truss void with gusset plates spreads fire horizontally through concealed channels and can fail suddenly with little external warning. A fire anywhere in that assembly can produce early, widespread involvement that confuses origin, and the engine company's 12 m ceiling pull has now destroyed the pattern evidence that would have shown direction of travel. Note the pull in the report as a limitation, and look for directional indicators on surviving web members.
Answer to the conflict: you cannot close it on the current record. That is a finding, not a failure.
2. Is naming the space heater supportable? Identify the methodological error and state the classification and report language you would use.
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The error is a negative corpus: concluding a specific cause because no other cause has been identified, when no hypothesis has actually been tested and confirmed. 'Nothing else makes sense' is the definition of the fallacy, not a substitute for testing.
What the evidence actually shows: the heater's cord and plug are intact with no arcing at the plug; the receptacle has been removed and co-mingled in an unlabeled bag, so its condition cannot be attributed to that heater or that event; the fire's area of origin is unresolved as between the front of the garage and the rear wall; and the truss void has destroyed much of the directional evidence.
Classification: area of origin - undetermined or 'undetermined, with two candidate areas'; cause - undetermined. Use 'undetermined' explicitly rather than 'probable,' which is not a valid classification category.
Handling the adjuster: state in writing what additional work could resolve the open questions (heater examination, receptacle identification and examination, burn-pattern reconstruction, witness re-interview, multi-week electrical history) and the cost and time. Decline to backdate a conclusion to a Friday deadline. If the carrier directs a conclusion the evidence cannot support, that is a documented disagreement, not a drafting preference.
3. List the documentation and evidence-handling actions you must take now, and identify the legal exposure created by the pre-arrival events.
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Document first, then disturb: overall and mid-range photography of the exterior and both areas of origin before any further debris removal; marked photographs of the heater in its driveway position exactly as found; a written record, with names and times, of who moved what and who hosed the floor.
Fix the evidence chain: the unlabeled bag is a chain-of-custody failure. Segregate the receptacle, photograph it as bagged, label with date, time, location, and collector, and obtain statements from the personnel who removed it. If the appliance is to be examined, photograph and bag the cord and plug, document the prong condition, and notify all parties so the examination is witnessed. Do not cut, clean, or test before the opposing parties are notified.
Exposure: the homeowner's hose-down and the brother's relocation of contents are spoliation risks that will be raised against whatever opinion you reach, and the fire department's overhaul is a documented limitation you must disclose rather than bury. Write the limitations section before the conclusions section, because the limitations define what the conclusions can be.
Deliverable: a report whose conclusions are exactly as strong as the surviving evidence, with every gap disclosed.