It would not surprise me one bit if the trade for Brain Dead Drew and the drafting of McGahee were both mandates from Ralph, "Get It Done". TD's HC choices were influenced by Ralph, who won't open his checkbook for them. Puddinhead Williams over McKinnie, that's on TD. Losman is on TD as well, though at least he tried to correct the situation.
I still say his biggest mistake was extending Drew after the 2003 season. If Bledsoe doesn't sh## the bed against the Steelers, the Bills make the playoffs in 2004, and the last 10 years would've been radically different for the better.