Episode 5 question

Sorry if this has been posted - I haven't scrolled through for fear of spoilers, as I just completed episode 5.

Why does Mal (the guy who's been escorting Darren?) stand at the window and allow himself get shot up prior to dropping the grenade? I know he had been shot in the neck anyway and was likely a goner anyway, but he could have easily had a quick glance out the window then chucked out the grenade, but didn't. It really stuck out as odd in an otherwise great (and brutal!) ep.