These are tricky, especially when your screenshots don't do much to help.
In the future, don't be afraid to spam the F2 key and pick out the helpful ones from the bad.
In these "proofs", he's merely holding flint & steel or a diamond sword. Your health is not effected. There's nothing in chat to prove that he did this all with intent. I'm sorry if I sound like I'm disbelieving you, but I can't make any sort of decision with what little you have given me. I apologize.
Did anyone actually die from this? If they did, I'll pursue this further [requesting logs to see if he admitted to doing it or said anything about it], but if no one died, then I'm just going to have a talk with the person and lock this topic.
