Maybe it's because I'm not familiar with norms around "Startup Weekend" type events.
I have no doubt Billy the pitch man is an asshole (almost all restaurant owners are, for one thing). I also think he's being completely reasonable being confused about why this guy he just met thinks he should own a piece of Billy's company.
But I confess I've never understood why anyone would want to go to a 'startup weekend' kind of thing and code for free on someone elses business idea, someone you've just met, in the first place.
I must be missing something about the general cultural expectations of such events.
But it does seem odd to have an event focused on starting businesses (and creating teams likely to work together in the future on the business?) among people who have just met, with no written contracts involved (even prohibited!) based just on cultural expectations which may or may not be shared, and no time to discuss them or get to know each other in advance. Do successful teams actually get created from this process sometimes?