Using this hypothetical:

A professional baseball player brings a defamation action against his former personal trainer and an online sports-news website based on a news article on the website that the baseball player used performance-enhancing drugs. The baseball player is also suing the website based on alleged defamatory statements posted by anonymous Internet users in the comments section attached with the article. The personal trainer also made statements to the FBI as part of a federal grand jury investigation involving the use of performance-enhancing drugs. The former trainer stated he has videotape evidence of drug use that he turned over to the FBI.

What defenses will the personal trainer likely assert in the defamation action?