to Howell, he either had to back off and give him space (and time to grow into the position), or come in and cut his legs out from under him. It's a hard call to know when to switch from one to the other.
We all wish he had made the change earlier (or that he never would have put himself in that position by giving Howell more trust than he clearly could handle). But I can understand why he didn't immediately step in and fix Howell's mistakes once he started down that path.