Everyone has gone way over the top with this! I doubt there is a crew member out there who can say they have never cracked a joke about doing something to someone's food, be it passengers', other cabin crew's or pilot's. Until someone actually does it and it can be proven just get over it.
I operated a flight the other day and when one of the engines was shutdown during taxi, the FO turned to me and jokingly said they'd thought about doing it during the cruise to save fuel. Going by what some of you are saying here, should he not have said that? Do you consider that comment inappropriate? Should I be demanding that the company investigate it?