We had no official ethics courses that I know of, aside from possibly something in the social sciences dealing with ethics in research, but our entire school was made to sign a very specific Honor Code when we first arrived on campus. We were bound to report (and there was a vehicle for doing this anonymously) any infraction of the honor code that we witnessed or were approached about and it would be dealt with. Even if it didn't teach us specifics of what we needed to do in order to cover ourselves in such a situation, it made us much more wary of doing anything unethical. I think something covering any legal options we had in such a case would be of great benefit.

Currently, any changes we're asked to make to any data is almost always due to a fumble-finger error on the part of a user, and we need documentation from the user authorizing it. We take a backup of the data before we change anything so we both have an audit trail and information on what to put back if we're asked to later. None of this has been anything the least bit dodgy though. I'd hope that the people I work with and I are ethical enough that we'd make the same kind of audit trail if we had to make the changes, if for no other reason than that we'd have some kind of documentation of what was done when we reported it. I'd also hope that all of us are ethical enough to refuse to do it if possible and document and report it later if not. But as someone said above, you never know what you're going to do until you're faced with the situation.