Breaking Bad Season Finale--Medically Accurate?

I've watched Breaking Bad since the very beginning and, quite frankly, I've seen a lot of disgusting things. Besides watching a moral human being erode into a calculating killer, there has been a significant amount of violence & bloodshed. Let's see, I've seen a decapitated head placed on a large, desert turtle (which was wired to explode), I've watched somebody bleed out after being stabbed with a box cutter, and, of course, the people melting. Chemical compounds have been used--a few times--to liquify people. 

There is generally a reality base to Breaking Bad's gruesomeness, but last night's season finale was rather puzzling. Simply put, the leader of a drug cartel has half of his face blown off in an explosion. Literally half of it is gone, as we can see his skull. (It's gross, I know.) Following the explosion, he takes a few steps, straightens his tie, & collapses. I'm no medical expert, but is this in any way possible? I realize it's fiction and they were obviously going for shock value, but can your body operate of its own volition, perform a simple physical act, without requiring use of the brain? Can your body exercise this muscle memory moments before you expire? It's disturbing, but it has made for some interesting discussion.