What were you supposed to do, bring it home, find the owner and do a handover? 
I can do one better. I was staying at my DMs and was looking at the local fb group. Someone posted that they had found a dead ginger cat that had been run over, at the end of DMs (small, very rural) road.
DM has a cat, and I've only seen two other local cats, one of which of which was ginger and lived at the neighbours at the back. Knowing I would want to know, and having had cats disappear before and never finding out what happened to them, I plucked up the courage to go round, even though I've never met them.
I knocked, and a woman answered the door with two very young children playing indoors behind her. I told the neighbour what I'd seen on fb, and just said I'd want to know if it was me, and left it at that.
Her ginger cat appeared in DMs garden a few days later.
I told the poor woman her cat was probably dead and he wasn't 
I stay away from fb now 