Rook took such a protective role more often than not that he sometimes forgot about using a sparing match for himself and being the aggressor to let off steam. That meant he wasn't quite as good at it as he probably should be, especially if he was thinking about taking the agency's offer soon, but there is was. It didn't help that he was distracted as well, making him no match for someone like Dax, who did this everyday.
It was frustrating, knowing he had weaknesses and not seeing them before his friend exploited them, as evidenced by the sounds of irritation that came out of his mouth, but Dax probably didn't need to hear them to know how he felt; they'd been friends long enough to be pretty good at reading each other's body language. Not that Rook was in a very good mindset to read Dax's with any sort of accuracy; he had trouble telling something was wrong even on a good day.
A good blow to his stomach lost Rook his footing and he went down on one knee, his hand going to his side automatically. "Don't go easy on me," he said, somewhat sarcastically; he could tell the other man wasn't really holding back, and yet he felt like maybe he was a little, and the part that was sincere wished he wouldn't.