Is it?
First, if someone jokes around and then says it was just a joke, is there really reasonable doubt? I’d rather call that “unreasonable” suspicion.
Second, if there is reasonable doubt that you are murdering people, you will not be punished unless it can be proven beyond reasonable doubt. Why should people be forced to have a career change if there’s no real reason to believe that they actually did something like that?
Okay, so it might not be a forced career change, because the next restaurant might just hire him because they know he’s innocent, and the Internet lynch mob will never find out that the new chef at that other restaurant is the same guy. Which only goes to show that firing him didn’t make much sense in the first place - if he was actually in the habit of preparing stealth anti-vegan dishes, why shouldn’t he continue?
Sure. A wage slave sullied the reputation of his masters by saying something in public. And the master’s reputation is valuable to the master, so the master must act to protect it.
How about “We’ve investigated the matter and found no evidence that this was anything more than a joke in bad taste. Furthermore, the work processes in our kitchen ensure that it would be impossible for a single employee to slip in any unwanted ingredients without other employees noticing”?
Anyway, the reason the managers feel forced to fire people over things like this is the Internet lynch mob that demands blood. And I won’t participate in that, even if I was convinced that the person in question was an asshole.
Keeping a job is not a luxury, so it should not depend on how often you’re an idiot outside your job, on your political views, or whether you get into fights with vegans, Arcturans or the entire Orion Syndicate on the Internet.