"Unsportsmanlike"? Bullshit. Note to Gabriel Krizan: that "ding" sound you just heard means get your ass ready to fight, not "touch gloves". You want to do a noble gesture, do it before the round starts.
The punch was completly legal or course. But sportmanship doesn't have to do with rules. It's about the nature of sport and the spirit of competition. I don't feel any sypathy for the guy with the knocked off block, but I'd never be a fan of a fighter who wants to win like that.
Or more aptly, if you're going to touch gloves after the bell, do it at arm's length. It may be a cheap shot, but from the vid it looks like he caught him with a hook, which means this guy is way too close.