Though it is probably too late to reverse now, the ideal scenario emerging from a conclusion like this, where aedan's vote swap is too late, is that aedan and ramius are lynched, and brovahkiin is auto-lynched for failing to vote on the last day.
Honestly, I'd support a "in-general" rule, where, if you (intentionally or otherwise) fail to vote on the last day of voting, you are considered to have lost.
It doesn't prevent a baddie from counting towards parity if they forget to vote, but they wouldn't win with their team.
It would prevent a situation like this from occuring in a gray zone again, while also encouraging other people not to act as aedan and throw away the game to prevent such people from winning, as there will be a mechanism in place to moderate that.