Talk about conspiracy theories!
Which part? The part where Sanders's team accessed the data they weren't supposed to? The part where they saved it? The part where they started fundraising off it after deflecting the blame? The part where his team has screwed up at every opportunity and given themselves a number of self-inflicted wounds? Or the part where anyone else would have been run out of the primary for doing this by now? Because outside of that last point, all of that stuff has actually happened.
Do I think Bernie had anything to do with this? No. I just think his team is wildly incompetent and figured they wouldn't get caught. Given their actions before this it's a safe bet to make.