Bobby never said he owned it. He didn't have hidden agendas going into the competition.
Billy says he owns it. Billy did have a hidden agenda.
Bobby at least owns a lot more than 0.04% of the company.
Had Billy hired the coders to do the work and say I own the company, I have no problem with that. But here, Billy tricks people to work on a project without fully disclosing his intention for virtually free, and than he claims he owns the company.
Unless Bobby has fabricated the emails and slack conversations (and there are 8 other people in the world who would be able to refute them if they were fabricated), I think we've heard it, at least partially, from Billy's side, as well. What has been included is more than damning enough; the email detailing "ownership" is all I need to see, given the terms of Startup Weekend (which are easily verifiable by looking at the website).
Billy came into the weekend with the intention to commit fraud on Startup Weekend and on any developers he could sucker into working with him.
I can't see either side being 'right' here.