At this point, I'm tempted to just sheep faust here. He is an IC--and I do have faith in his reads I think.
It's kind of lazy of me, but I'm just not seeing how Volt isn't going to be suspected at this point. If we don't lynch him today (assuming we don't get the last scum), we'll probably just lynch him tomorrow.
For the record, if Volt flips town, I think we should look amongst the people who defended him for scum. The last scum needs to survive quite a while in order to win, and it'd probably look better for them to be off town wagons as much as possible. This is much easier for them if they aren't someone who is likely going to get lynched today too--so they can push an alternative lynch instead, and then push that lynch again tomorrow when Volt flips town.
Otherwise, I consider Volt a very capable player, and I've been burned before by people downplaying their ability to play scum see: Musical Mafia
He's also been away for a while, so his playstyle could be different.