I have watched this video repeatedly and I can say with 100% certainty that this kick was legal. He was on his feet and standing back up at the time when he was kicked.
Uhhhh...What you're saying matches the pictures above except you are leaving out where his hands are. According to the rules, if his hands are on the mat, the kick is illegal.
However, on a personal note, I don't think that split second of his hands being on the mat or off it should matter. Nothing would have been different if his kick had landed a split second later. The guy is trying to win on a technicality.