If one person comes forward claiming to have pressed the button, this market resolves to that person, unless they're known to be a troll or otherwise unreliable.

If multiple people make that claim and there is no way to tell who's telling the truth, this market resolves to all of them, with equal probability.

The same applies for someone presenting evidence in favor of a specific other person having pressed the button.

If no credible candidates have been presented by the end of the year, this market resolves N/A.

This market is only about the second, legitimate press at 200+ karma, not the early one that was allowed by a bug.

This is inherently a subjective market with regards to determining whether a certain claimant can be trusted. I will attempt to defer to the community for this decision; if there's a strong consensus in the comments as to how I should resolve the market, I will resolve it that way. My judgement will only come into play if the community seems split.

(Note that the structure of this market means there's an incentive for someone to bet on themselves and then falsely claim they pressed the button, and it's going to be hard to falsify that. Take that into account when betting.)

I reserve the right to modify the rules of this market if someone else presents a different scheme that better captures the spirit and is less vulnerable to deceit.