I am so sorry that I just got back to this. I've been busy IRL
And the Question was confused for a moment, the gravel trick usually worked against skilled opponents. He was starting to realize exactly how outclassed that he truly was in this fight. When he realizes that Cassie had swept around behind him, he will quickly turn and face her. There is a nervous tic to his body language. He's not happy at the moment.
Not happy, but kind of exhilarated. This is the best fight he's had in months. The thugs and punks of Gotham have nothing on this person right here.