Why should that even have to be a hypothetical? The answer is no, they didn't have to do that at all.
How do you know?
I doubt it, but again, we don’t know all the facts, and a jury acquited them - after supposedly weighing all the evidence.
The fact is, unfortunately, this was an incidental injury. Damaged trachea is not a normal consequence of typical police confrontations, so in all likelihood it was accidental.
I’m guessing at worst manslaughter.
This isn’t to say perhaps they were beyond reason, as was the owner, but actually criminal? Maybe, maybe not.
OTOH, if there really were 3 guards (not acting as police BTW) over him - why? 3 people seems like overkill to confront this man.
God bless his family for their terrible loss.