Rugrat would have had to claim anyway with the mass claim. The only real criticism you could put on him for that would be that he could have anticipated that his shot would be messed with and held fire, but I think it's a little unfair. His main mistake was shooting Doddsy.
I think it's easy to forget as well that Mafia had lovers. If those died early that's 2 scum lost and if the JoAT was caught they'd be outgunned (the Mafia complained in their chat about the extent of their power). I think I tend to agree that this game was more everything going wrong for town that could go wrong - early mislynch, duel not being used to kill scum but on an extra vote, modkill, walking into an execute, misvig, and the choice to take out the Serial before Mafia.