It’s not a matter of doing it over. Much of the information proving Obama is a fraud only surfaced after the election. The timing doesn’t relieve Obama of a positive burden to prove his eligibility.
He has no such obligation. Not a legal one anyway. The timing does matter because the election is over. The electors voted, the Congress certified it and Obama was sworn in. It's done.
And let's not forget that any positive obligation he had prior to all that, he met. He was after all listed on every ballot, and won. So I don't know what obligation is imagined that he failed to meet.