Thanks for pointing that out, I forgot to include it. You are right, the guide did try to destroy the collar when he found it. That part is certainly a crime, but on the part of the guide, not the hunter. I’m not sure if the hunter knew about that detail. He may have known, may not have known...
Given that both client and guide apparently realized Cecil was collared you would have to have a disregard for common sense which beggars belief to argue that Palmer wasn’t aware of what happened to it.
“I was devastated. I could not have seen the collar at night. We would never shoot a collared animal,” Bronkhorst told them. “I was devastated, and so was the client, we were both upset, and I panicked and took it off and put it in a tree. I should have taken it to Parks, I admit that.”