Yes, at this point Bennett would have to know what was going on, if he has any sense at all.
And for him to be pressuring Arpaio to end the criminal investigation suggests that either he sides with what he knows is the “bad guys”, or he’s afraid to stand up to the “bad guys”, or he’s been threatened by the “bad guys” to try to get the good guys off their tails.
If the Joe Arpaio Posse is able to expose the bad guys for all to see, Bennett will be revealed as an idiot. So he now has a vested interest in Sheriff Joe not finding anything.
Bennett can throw a hissy fit all he wants. Arpaio is not investigating eligibility to be on the ballot. He is investigating criminal fraud. The SOS has nothing to do with that. Arpaio can just tell him to kiss his a$$. He had his chance.