Thanks for sharing, Bobby. As someone who has participated, volunteered, and won at a couple different hackathons (including Startup Weekend), I am sorry your experience was so terrible. It seems stories like this keep people away, but I think a lot more people — especially people new to tech or exploring the world of startups — benefit greatly from learning about people like you. Their foray into the world of tech usually brings and enthusiasm to help in whatever way they can.
As for the business side of things, I think your cautionary tale brings up a good practice I have started doing, namely: if I’m contemplating working on an idea that I have not pitched, I do as much due diligence I can on the person pitching it. This includes a perfunctory web presence search (Google, LinkedIn, etc.), and getting tough questions at the outset — where did this idea come from, prior efforts, etc. Setting expectations first, at the outset of the project, can help alleviate any misunderstandings, etc. Red flags went up when I read the first inkling about stock warrants, etc.
Hopefully, your next experience with a hackathon or SW will fare better. You and your team of veterans certainly don’t need a Billy to win.