## Facts

- Nucor Corporation sued former employee John Bell and his new employer, SeverCorr, LLC, asserting misappropriation of confidential business information and related claims.
- During discovery, Nucor accused defendants of “data wiping” and other conduct that destroyed or altered electronically stored information (ESI) on Bell’s SeverCorr laptop.
- Nucor’s spoliation accusations also involved other media associated with Bell’s transition from Nucor, including a USB thumb drive and a CD Bell created shortly before leaving Nucor.
- Nucor moved for spoliation sanctions, seeking severe relief (including striking defendants’ pleadings/entry of judgment) or, alternatively, an adverse-inference instruction.
- Each side offered computer-forensics testimony on whether the laptop showed signs of wiping and what inferences could be drawn from artifacts on the drive.
- The parties filed cross-motions to exclude the other side’s computer-forensics testimony under Federal Rule of Evidence 702 and Daubert.
- As to Nucor’s witness, John Jorgensen, the court found, among other things, that:
  - Jorgensen abandoned all but his most recent theory of what explained the alleged wiping.
  - His data-load progression testing produced replicable results supporting some opinions.
  - He withdrew an opinion concerning a hyperfil.sys file on Bell’s laptop.
  - One opinion relied on an inexact comparison between “Collingwood” computers and Bell’s laptop.
  - His assertions about Ultimate Cleaner and Ultimate Defender software were either untested or contradicted by information from the software manufacturer.
- As to defendants’ witness, Sean McLinden, the court found, among other things, that:
  - McLinden was trained as a physician but had worked in computer forensics for decades.
  - He validated some views through Internet chat-room communications with other computer-forensics practitioners.
  - He did not consistently use best practices in copying the laptop drive, but he used copying software that many practitioners viewed as reliable.
- The court then determined what testimony, if any, should be excluded and what sanction, if any, should be imposed for spoliation.

## Issues

1. Whether, under Rule 702 and Daubert, Jorgensen’s opinions on alleged wiping and related artifacts were sufficiently reliable and supported to be admitted, in whole or in part.
2. Whether, under Rule 702 and Daubert, McLinden’s rebuttal opinions and handling of the drive supported admitting his testimony, in whole or in part.
3. Whether defendants spoliated relevant ESI, and if so, what sanction was appropriate (default-type relief or an adverse-inference instruction).

## Decision

- The court granted in part and denied in part the cross-motions to exclude, permitting testimony supported by reliable testing and record support while limiting or excluding discrete opinions that were withdrawn, untested, based on weak comparisons, or otherwise insufficiently supported.
- The court treated several attacks on methodology and credentials as going to weight, not admissibility, and allowed the jury (or factfinder) to consider those disputes through cross-examination and competing proof.
- On spoliation, the court found that defendants failed to preserve relevant electronic evidence and that the loss or alteration of ESI warranted sanctions.
- The court denied Nucor’s request for terminating sanctions (striking pleadings/entry of judgment).
- The court imposed a lesser but meaningful sanction: an adverse-inference instruction concerning the destroyed or altered electronic evidence.

## Legal Principles

- Under Rule 702, computer-forensics testimony must rest on sufficient facts or data, use reliable methods, and apply those methods reliably to the evidence examined.
- A court may admit an expert’s testimony in part and exclude specific opinions when they are withdrawn, untested, contradicted by the record, or based on an unreliable comparison.
- Disagreements about an expert’s background, validation sources, or imperfect handling of forensic tasks often affect weight rather than admissibility when the core approach is reliable enough for the factfinder to evaluate.
- Spoliation sanctions turn on whether the party had a duty to preserve, whether relevant evidence was lost or altered with a culpable state of mind, and whether the loss caused prejudice.
- Courts have broad discretion to tailor sanctions to the misconduct and prejudice; terminating sanctions are reserved for the most extreme situations, while an adverse-inference instruction may be appropriate when relevant evidence was wrongfully destroyed or compromised.

## Conclusion

Nucor Corp. v. Bell addressed competing computer-forensics testimony about alleged data wiping and, based on the court’s reliability and record-support findings, allowed some opinions while trimming others; the court also found ESI spoliation and imposed an adverse-inference instruction, rejecting Nucor’s request for default-type relief.


Nucor Corp. v. Bell, 2008 WL 4442571 (2008)