Don't start trouble with boxers.
Of note: He's walking with her on his left arm. To me, that says he's right handed... but it's his left he uses to drop both of them. I agree he's a trained fighter, not sure in what discipline, but people expect the right handed haymaker, and are ready for it (not that that always helps, mind you) I read somewhere (maybe here) that a gut punch or a left tends to come as a surprise and is a good way to maybe win a fight you haven't been able to avoid.
Just a thought... and yes, it served the both of them right. Or left, in this case.
Blessings,
Bill