I also agree that at this point it's not fair to blame him anymore. The administration (Hamilton) royally screwed up choosing a successor, and Dooley was one of the worst coaches in the history of UT athletics.
I'm not blaming Fulmer directly for what's happening now. The roster problems he left were a primary factor in UT's losing and problems for the last 4 years so indirectly he has continued to have an impact. If he doesn't run it into the ground... rebuilding would not have been necessary.
Dooley was a terrible football coach. He did however leave the roster to Jones better than Fulmer left it to Kiffin and much better than Kiffin left it to him.
Dooley was hired because the job was pretty undesirable at that point. I personally do not think an interim would have made anything better at all. In fact, it probably would have resulted in a '10 signing class about half the size of the one UT signed and without Hunter, Stone, and other impact players.
Kiffin was the big mistake. With hindsight in full 20/20 now, I do not think he would have ever become the "right" coach for UT. I think the chances for very serious NCAA problems were MUCH greater than him competing for championships in K'ville. The BEST players Fulmer left were the Srs of 09- D Williams, Hardesty, Jones, Moore, McClendon, Scott, Richards... There were many guys willing to start with that roster and try to build. There are probably many who could have found a way to discipline guys like Creer without kicking them off the team.
Kiffin used up the narrow window then bolted... so with a roster that didn't have a QB... or a returning starter on the OL... no depth... holes all over the D... UT only managed to take a long shot on Dooley. He was likely one of many risky options.