I don't think the "street fighter" threw a single punch. He was completely and utterly inept. The iron palm master worked him like a puppet, but he couldn't end the fight with a knockout or a throw. Yes, he just bitch-slapped him, because the street fighter didn't do anything. Someone with one year of Western boxing training would have knocked the street fighter cold. A bjj white belt would have choked him out. Come to think of it, they'd both probably do the same thing to the iron palm master.
I knew this criticism would be coming. Before trying to explain the fight further, let me ask you : is it always the case that a fight should be "equally-matched" from both sides? Clearly, in cases where one man's skills far exceed the others, the other guy looks "utterly inept".
1. If you watch the video properly, you will see that the boxer isn't actually "utterly inept" who's a defensive player. He did begin to advance in the beginning of the fight, if you watch closely, but after tasting the iron palm effects, it was his natural body's reaction to play defensive.
2. As for your comment about the guy being a pussy, he is well built and is quite large (98 kg). Even if he didn't know how to fight using boxing, would you have wanted to fight against him? If it wasn't the iron palm master but a random 60 kg dude who was deluded to think that he can fight using wushu, then he would have been owned.
I will help you to imagine the situation properly. Imagine that your two best MMA/BJJ players are fighting. If you hand over a knife to one of them, would the other still fight the same way? Or more defensively?
The Iron Palm skills of this guy are equivalent for that "knife". It serves the same purpose here as if he was holding a leather belt or a knife. Only difference is that he has conditioned his hands to produce the penetrating force.
You can be dismissive as much as you want, but I can assure you, after actually getting hit by an Iron palm, you would be more apprehensive of fighting the little dude than the larger boxer in that video.