Holmes starts and looks down at Moran, but it doesn't seem likely that he'll do much more than moan just now. Still, they need to hurry, and maybe it's good that they can't talk about what just happened. Holmes tries to read Watson's reaction as he (a little uncertainly) takes his hands off Watson's body and steps away from him completely.

It's an effort -- even through the situation's urgency -- to draw away from Watson and blow on the police whistle. The men Lestrade sent (and Lestrade?) will be here shortly, and as much as he'd like to be alone with Watson, maybe the forced aversion of what just happened would be good for them.

Watson had kissed back. He should be deliriously happy about that, but it had been an adrenaline-rich moment; Watson might regret it later.

He's glad to hear the officers stomping noisily up the steps, so he doesn't have time to say anything to Watson.