It's like none of you watched the video. HC is clearly moving down the sideline to talk/chew out the DC. He doesn't even see the opposing QB, who was forced out of bounds and happens to come out of the crowded sideline right as Smart gets there. Smart never once even looks at him, pushes who is in front of him out of the way, and continues to converse with DC. At no point does he even look at the player he pushed. The QB doesn't react; two officials standing within two feet of this "horrible incident" don't do anything, and neither the coach nor the QB say anything and call it nothing later. It couldn't be more clear this is the type of thing that can happen on a chaotic, crammed-in sideline in a football game. There was never any intention to harm anyone, and it wasn't even that hard of a push. No one was hurt, the coach continued to go to the DC and carry on like nothing happened because to him nothing happened. The game continued on, and until some people saw it on social media it was total nothingburger. The coach didn't even know it had happened until it was brought up in the presser after the game. He said he had no recollection of it. After looking at it later he called the other coach to apologize, and then called the player to apologize. Neither were bothered by it.
I am done defending it because anyone who looks at this in context understands what happened and that was nothing.