## Facts

- Ronald Biles worked as an insulator for a subcontractor during construction of an oil refinery built for Humble Oil (Exxon Mobil’s predecessor) from October 1968 to March 1969.
- In October 2001, Biles was diagnosed with asbestosis and asbestos-related pleural disease.
- In April 2002, Biles sued Exxon Mobil under a premises liability theory, alleging asbestos exposure at the refinery.
- During discovery, Exxon served interrogatories asking Biles to identify individuals with knowledge of his asbestos exposure on Exxon’s premises.
- In May 2003, Biles responded that, after a reasonable inquiry, he lacked responsive information, and he reserved the right to supplement.
- In opposing Exxon’s motion for summary judgment, Biles relied on deposition testimony and a declaration from Roger Bellamy (taken in a different asbestos case), asserting Bellamy worked with Biles at the refinery and that Exxon employees used compressed-air hoses to blow asbestos dust through work areas near Biles.
- Exxon objected that Bellamy was not disclosed in interrogatory responses or supplemental responses.

## Issues

1. Whether California law imposes a general affirmative duty to supplement interrogatory responses when new information is discovered, including where the responding party “reserves” the right to supplement.
2. Whether a trial court may exclude previously undisclosed witness evidence as a discovery sanction in the absence of a willful failure to comply with a court order compelling further responses.
3. Whether Bellamy’s testimony and declaration, if considered, created a triable issue of material fact sufficient to defeat summary judgment on premises liability.

## Decision

- The Court of Appeal reversed the summary judgment for Exxon Mobil.
- California law does not impose a broad, free-standing duty to supplement interrogatory answers merely because new information is later obtained or because a party reserved the right to supplement.
- The trial court abused its discretion by excluding Bellamy’s evidence as a discovery sanction where Exxon had not obtained, and Biles had not violated, any order compelling further responses.
- Considering Bellamy’s evidence, a triable issue existed as to Biles’s asbestos exposure on Exxon’s premises and Exxon’s potential liability.

## Legal Principles

- Absent a specific statutory requirement or a court order compelling further responses, there is no general duty to supplement interrogatory answers under California discovery law.
- Evidentiary discovery sanctions (including exclusion of evidence) require statutory authority and, for nonmonetary sanctions, generally require a willful failure to comply with a court order compelling discovery.
- In the absence of a properly imposed evidentiary sanction for discovery abuse, previously undisclosed evidence is not categorically barred from use in opposition to a summary judgment motion.
- Summary judgment is improper where admissible evidence raises a triable issue of material fact on exposure and causation elements supporting premises liability.

## Conclusion

The court held that a party’s failure to supplement interrogatory responses, without violation of a court order compelling further responses, cannot justify excluding evidence, and that the excluded witness evidence created a triable factual dispute requiring reversal of summary judgment.


Biles v. Exxon Mobil Corp., 124 Cal. App. 4th 1315, 22 Cal. Rptr. 3d 282 (Cal. Ct. App. 2004)