There wasn't much that could be done. According to the rules, all's fair so long as the code wasn't written until the hackathon itself, which is pretty much impossible to prove or disprove anyway. You can prepare as long as you want. There is a section about a "code review" but I doubt that was really done; IIRC we didn't even submit our code, we just did a demo & video.
The strongest complaint we could make was that it was strongly against the spirit of a hackathon, which is a difficult argument to win.
The strongest complaint we could make was that it was strongly against the spirit of a hackathon, which is a difficult argument to win.