Suppose a cop tripped over a students water bottle, hit his head on the ground and died. Did the student murder that cop?

Sure, if the student intended to harm the cop, and slipped it directly under his foot when he went to step. That would be a fair equivalent, and I would say yeah, the student is in the wrong.

I think the previous user's reversal comparison was a bad faith rhetoric trap. A good faith reciprocal comparison would have been something like that :

Suppose that a student brought an explosive device to the protest, primed it, then threw it at the cop or in their vicinity, and that the device's explosion maimed the cop. Did the student maim the cop ?

Considering your answer, which I agee with, we would probably both answer "Yes" to this question. In my opinion, as in the real case where the student was maimed, whether the victim did make the right decision to handle the explosive menace or not is not relevant.

You can't throw something intended to harm others, and then cry fowl. The cop is the reason that students hand is gone. No clue why you would say otherwise, except to victim blame.

Exactly. A "weapon by nature" (designed to be used as weapon in the first place) was used by the cop, so this cop carries heavy responsibilites for the consequences of their action.

if the student intended

Its interesting you consider the students intention.

What do you suppose was the cop's intention?