Sure, but they probably want to know who was in the room with him, what was their reaction, what was his reaction, did they realize anything was immediately wrong? did they know who to contact? etc...
If an air traffic controller was involved in a plane crash in a non-culpable manner, I'm sure people would feel very strongly that he should cooperate with investigators. Why is this situation different?
> Pursuant to section 701(e) of the Federal Aviation Act of 1958 (FA Act), and section 304(c) of the Independent Safety Board Act of 1974 ( 49 U.S.C. 1154(b)) (Safety Act), no part of a Board accident report may be admitted as evidence or used in any suit or action for damages growing out of any matter mentioned in such reports.
From the link in basseq's response to my question: "The investigations are meant to be litigation neutral in order to promote impartiality and foster cooperation so that the NTSB’s mission of finding the cause of an accident can be accomplished in order to prevent similar ones
from occurring."
Crucially, the National Transportation Safety Board's purpose is to make safety recommendations, not to enforce law.
If an air traffic controller was involved in a plane crash in a non-culpable manner, I'm sure people would feel very strongly that he should cooperate with investigators. Why is this situation different?