How much effort is he willing to put into helping this cat? What I mean is, is he prepared to call all the local rescues and vets and put up posters regarding him? (I assume it's an unneutered tom.)
General was a stray, I asked around and noone seemed to know where he'd come from - I never put the posters up, because he was in such a state that it seemed the only likely option was he was a stray. That and his behaviour with people indicated he wasn't sure how to be around them.
I raised funds to get him neutered and chipped and then ensured he had a safe new home to go to he'd feel himself in.
Would the chap be prepared to help this cat, and in turn help his own animals? Or is that not a possibility?