For most of Wednesday, the U.S. Senate race recount in Sibley County operated smoothly, seemed to prove that the ballot-counting machines had performed flawlessly on election night and provided one additional vote for Democrat Al Franken.

But one of the last townships counted provided a one-vote flip — from Franken to Republican Sen. Norm Coleman — and there was no ready explanation for why it happened.

That switch eliminated the one-vote pick-up Franken received when the manual recount spotted a Gaylord ballot where the voter had put a check-mark to the right of the Democrat’s name rather than filling in the oval to the left. The counting machine missed that vote and the voter’s presidential preference, which was also made with a check mark outside the oval.

Farther down the ballot, the voter filled in the ovals as the ballots instruct.

“He must have decided to read the instructions (part-way through),” said Aaron Scharpe, a Sibley County deputy auditor.

To gain ground — albeit a single vote — probably would have been a victory for Franken considering Sibley County gave him just 28 percent of its Senate votes on election night. Franken went into the start of the statewide recount Wednesday trailing Coleman by 215 votes out of nearly 3 million cast.

Ultimately, though, the discovered Gaylord vote didn’t reduce Franken’s deficit to 214.

The change in Dryden Township gave Coleman 68 votes rather than the 67 reported previously, and Franken 37 instead of 38. So that means the final count for Sibley County will most likely provide Coleman with one additional total vote, with Franken staying even because the added vote in Gaylord was offset by the lost vote in Dryden Township.

There were three challenges to the vote determinations by election officials — two by a Coleman representative disputing a pair of Franken votes and one by a Franken representative of a Coleman vote. In all three cases, the voter intent as defined under state law appeared to be clear, and the challengers at times had trouble explaining specifically why they were challenging the ballots.

The three ballots were set aside and will be examined next month by the State Canvassing Board, a group of judges and Secretary of State Mark Ritchie, for a final decision. If the challenges are judged to be without merit, the final totals in Sibley County will be 3,499 votes for Coleman and 2,158 for Franken. The unexplained change in Dryden Township clearly vexed Sibley County Auditor Lisa Pfarr, who asked the lead representatives of the two campaigns if they’d agree to one more count of the township votes.

“I want to make sure this number is right,” Pfarr told them.

But by the time Pfarr was aware of the change, the recount team that had handled the Dryden count had sealed the envelope.

The Coleman representative sought advice from the campaign’s recount lawyers, who responded that they would agree to reopen the envelope only if Ritchie consented. Pfarr made a call to Ritchie’s office, and she was told to not reopen the Dryden count.

“Status quo,” Pfarr announced. “We will not be recounting.”

The count of the township, like all others in Sibley County, had been watched closely by representatives of both campaigns. Neither challenged any ballots cast in the township, and the ballots were counted by two separate election workers.