What determines a "lucky punch" to you guys? If the same punch and same results happen in the 3rd round, still lucky?
Kimbo Slice is 30lbs heavier, 2" taller, has a 4" reach advantage, the beginning of the video says he didn't know he was fighting in the main event until he got to the arena that night, and he's fighting a guy with a big name. Celebrating and adrenaline are pretty common when someone gets ko'd especially in those circumstances.
Kimbo's a street fighter with very little actual training compared to most pro's. Like you said the 1 sets up the 2, 90% of the population is right handed so it isn't hard to guess what's coming from a street fighter. The kid tries to keep him back with a push kick that kimbo runs threw. Pause the video at 48-49 seconds Kimbo's hips are square, feet a parallel, lunging forward with his hands at his waist and gets hit with right hand and that's end of his night. All these fights end with one punch ko's from overly aggressive sloppy fighting. I'd call it getting caught not lucky. Like most pro sports the person who makes least amount of mistakes usually wins.