If this dude figured out how to lift a full size duty weapon out of a retention holster using nothing but a plastic dino-grabber then he deserves to keep those guns.
That's the only reason, I think, that he was able to "repeatedly" do it instead of being arrested after the first time. Cop was so impressed that he managed it, he let him off with a warning and a handshake. Once is cool. Twice is funny. Three times is getting annoying. Fourth time is kind of embarrassing to the officers at this point. And fifth time is too far.
I doubt these were retention holsters. It wouldn't surprise me if he was doing it specifically to draw attention to how many cops are walking around with non-approved holsters.