Believe it or not, McCoy is also a scientist and also a fairly intelligent man who sometimes retains the information he comes across, so a backflash? It had definitely entered his mind, but he was willing to risk it just to get out of here.

He wasn't going to make it much longer here; he wasn't getting enough good air. (He was already running through all the things he needed to do to treat smoke inhalation.)

He was coughing too much to really say anything to Spock when he saw the already spider-webbed window in an alcove they were passing, so he urgently patted Spock's elbow and pointed.