“More importantly, if one is going to release it, the cat needs a strongly aversive treatment by humans so that it won’t chance such an adventure again.”
Effective aversive conditioning re: humans has only been successfully demonstrated by one group of professionals. As in all government agencies, California Panther Panderers show extremely aversion to employment of said successful ‘cougar conditioners’.
Google “Taxidermists”. Results are guaranteed. 100% success rate for over 150 years.
Note that no cat conditioned by a taxidermist has ever demonstrated threatening behavior towards any human.
I'll bet you could walk up a taxidermist to a mountain lion and it wouldn't bat an eye.
There isn't a mountain lion in history that has ever learned aversion or taught it to its young by dying. I agree that hunting is necessary, but it is not even a remote political possibility in this State.