Accurate vote tallying after the polls close depends on a pause in the announcement of the vote totals. Before the tally is announced, it is necessary to be sure that the number of ballots in the ballot box matches the number of people checked off the voter rolls as having voted. In this manner, doing this assures that there is a check against ballot box stuffing.
Balancing the vote totals against the number of people who voted is prudent. Before the vote totals are announced after the polls close, it is imperative that the officials governing the election determine conclusively how many people voted, were checked off the voting rolls as qualified registered voters, and make sure that number is in sync with the number of ballots counted.
An example of when this would have been prudent can be seen in July 2021 in NYC where confusion took hold amidst counting during the NYC Democratic mayoral primary. Election officials had to publically acknowledge a tabulation error. The Board of Elections said that “test” ballots were included in the ranked-choice voting tally it had released earlier.