You already have the main resource I would have suggested - - -
- - To evaluate any damage to the piece. I note in your illustration you already have a printout of the Jim March "Revolver checkout: how to tell if a particular specimen is any good" article.
A single instance of the "TV detective demonstrating his firearms ignorance" maneuver will not necessarily ruin the revolver. Much depends on the force used and other variables. If the revolver meets all the check out criteria, carries up, indexes properly, shows proper tolerances, and so forth, it is most likely fine.
If OTOH, your pal has made a habit of this stunt, he may well have damaged the M13 to the point where it needs extensive attention by a good gunsmith, or, better yet, a trip to Springfield, either of which can be downright costly.
Perform the checkout, with a very critical eye. Be honest with yourself and with the other guy. If the revolver needs repair, you can tell him, honestly, that a crane rebuild/adjustment could easily run $150, and you'd need to deal with him on that basis. If he hasn't damaged it, though, and he IS indeed a friend, rather than a casual acquaintence, you surely want to be fair with HIM.
I empathize with your "I want this gun" condition. I just recently picked up its stainless cousin, an M65-3 agency trade-in, for a fairly decent trade, and I'm becoming more and more fond of it.
Best of luck to you - -
Johnny