Watching throughout the video, there are two glasses on the table, and he grabs the one closer to him. Hers appears to be empty at this time.
not an appropriate response to her threatening him with the beer bottle
In a physical altercation, a beer bottle is considered a deadly weapon. We've seen too many Hollywood-style, sugar-glass bottles being broken over people's heads to really think of them that way, but the reality is that the shattering of a glass bottle in a fight can easily cause severe lacerations to the face, eyes, neck, etc. He had already shown that he was retreating from the altercation when she picked up the bottle and confronted him. That final shove was the most defensible act of the entire altercation.
The kick will be the hardest act for his lawyer to explain.