I too put credence in Sheeran's claim's at one point. Even Capeci did in his book Idiot's Guide. When you get a chance, try and read the latest Gangland article. It was written by Dan Moldea, one of the most well regarded Hoffa researchers ever, and in it he makes a good case for Sally Bugs being the actual shooter. It makes sense that, before he died, Sheeran wanted a way to be able to leave his family some $$$, and hence made the claims that he did.

My own opinion's have changed several times in recent years, but I am currently of the belief that, while Sheeran was a part of the conspiracy to lull Hoffa into a false sense of security, he was not actually the trigger-man.