I understand that the member is new and that these things happen. Essentially, the process is that, if the app does not work when a member is in the lobby or in any other situation, the member can come in and, after the vote has been called, get up and say that the app did not work and that they would like their vote to be counted one way or the other.
That is the proper procedure. The member's vote would not count unless he gets up and asks for unanimous consent for his vote to count.