Well, he had plenty of practice getting knocked down so that he could demonstrate his recovery skills.
I have this sorry ass phone that keeps changing the words I type in. It drives me crazy. I think my horse Bluto is controlling it from his stall in the barn. He is a very suspicious horse. Speaking of horses, Lupe Pintor would have stopped the Jeff Chandler of the Sandoval fight in the 1st round. He is lucky Richie had no punch.
Only fighters I can think of who's been dropped, hurt, and having good recovery while also never being stopped is Rocky Marciano, Felix Trinidad, Naseem Hamed, and Hector Camacho.
Sugar Ray Robinson was put down a fair few times in his long, long career and was only ever stopped the once (via heat exhaustion ironically). His chin was great obviously (as was nigh on everything about him boxing wise) but his excellent recovery was something that gets seldom mentioned about him.