Two things that make him fail. First he didn't confidence in his men. He always stayed behind in the vehicle (that may have been part of his job though), and he didn't order the vehicle in to support them when they needed it. His own caution (or fear) worked against him. And second the order to collect the clips was highly questionable. The order should have been not to fire them. Showing the men he doesn't trust them is a bad move.
Either way his failure seems to bother him so much he does not appear to resume command when he comes out of his concussion.
Anyway when he is calm he seems competent enough, but he buckles under pressure.