Yes, two crew is safer. Look at some of the other accidents that have happened in single crew ops. Two Loganair BN2 fatal crashes and the Mersey Chieftain crash that killed five.
I used to fly for an ambulance operator that did multi crew ops in a piston. I always felt safer knowing that the other guy was watching my back. I also did single crew ops. Based on being in the know, if I was told that I would be riding in the back of a single crew piston as a PAX, I think I'd suddenly rememeber that I'd left the taps running at home....