. As for the notion that McClain would know that Dunn wasn't dead: even if it was certain he would (and it's not), he'd probably attribute it to him missing rather than Dunn being a freak of nature. So then, to prevent Dunn from getting the upper hand, he'd have to shoot him in the head again while he was down. Otherwise, then he would have no means of being sure Dunn was actually dead, and Dunn wouldn't be affected. Again, Dunn can try to put the drop on McClain. Advantage Dunn. It seems even more likely that McClain wouldn't shoot him in the head to begin with, and then almost certainly think Dunn is dead. I really don't see the certain upper hand, and I think the fact that McClain has been portrayed as falling for the kind of thing that are part of Dunn's edge in his own film (being saved by his sidekick) really speaks against McClain as super-thorough-perceptive-scientist-killer. 