I don't think he should be suspended, obviously there are legal implications to destroying someone else's property, but that is what the law is for, not your employer.
100% support the student's right to free speech. But at the same time, you know the question is antagonizing the guy. Not a kind thing to do, but you also shouldn't have to fear destruction of your property over it.
I support free speech as well, but there are sometimes consequences to saying hateful and offensive things.
Consequences to actions yes, but there is law that limits what those consequences can be. Eye for eye, tooth for tooth. Not phone for antagonizing question. (It's still stupid to antagonize people, because if someone shoots you dead over something you said, you're still dead, whether the other guy goes to prison or not. The law doesn't
physically limit the other guy's retribution.)