That's because PHB has no idea that he's not actually facing right, as stated many times already (look in the first panel - PHB should be commenting to Wally)
Alice's line is a prediction, not an observation, of PHB looking right, since 2 tries is the maximum possible (given logical constraints) to find a side (left or right) and he's already wasted 1 try. Alice is making a comment to the effect that PHB doesn't know right from left. PHB hasn't looked right yet. I see no implication that he has looked right, and would be curious to hear how others have drawn this conclusion.
Uh, no Infiltrator. The second panel implies that he looked to his left once then looked to his right. What Mitch meant was he is still looking left. But seriously this the best description about teamwork ever. Everyone secretly (or not so secretly) doesn't really like each other.