I only asked because you brought up the point that they were out past curfew. For arguments sake, let's say that the man was out well past curfew and did attack the cops and that's good enough reason for pushing him. That still doesn't excuse the cop for not checking on him or calling for medial assistance even though that's part his job. If it was a fellow cop on the ground he would be checking on him right away.
A lot has been said about the man who should be responsible for his actions. If that's the case, the cop then who did the pushing also needs to take responsibility for his actions. I realize that he might not have the first aid equipment to deal with incident, but like I said earlier, it takes little effort to check on the man to make sure he's breathing, if there are any other injuries and call in his colleagues. Instead, he just silently walked past.