Declaring a tie sounds like the easiest option. The only question is how to handle that in terms of prizes - if both are happy with the contest rules they could decide together, or they could agree to put the money prize to a common cause (like a donation to the forums or to a mutually-agreed charity). Or of course, if one contestant decides they don't want it, the other could just have it. I don't think there's a serious problem with eg. that it'd mean 2 auto-nominations to LOTY2020.
If a re-vote is preferred, I suggest a delay before it takes place, combined with encouraging more people to look at the levels. For example - I didn't vote in this contest because I didn't play that many of the levels. But, if a re-vote was taking place for the finals, I might look at just those two levels and vote for one of them - which even if no one else changed anything, that would give us a tiebreaker. (Of course, there's the chance other people do the same, vote differently from me, and thus we end up with another tie.)
