John L. Zalusky has served as an international election observer in emerging democracies such as Bosnia, Serbia, Belarus and Kosovo. But he said his most trying poll-watching experience came Tuesday at Patuxent High School in Lusby.

"I've never been treated this badly," said the 70-year-old Drum Point resident.

Zalusky, a poll observer for the local Democratic Party during last week's voting, was removed from the polling site early Tuesday afternoon by two Calvert County sheriff's officers and one Maryland State Police trooper after he complained that election judges were violating the law.

The Calvert County Board of Elections had instructed poll workers not to hand out provisional ballots to people who were not listed in a state-wide database of registered voters. Zalusky, who said the policy violated the federal Help America Vote Act of 2002, instructed prospective voters who were not on the Calvert rolls that they could demand a provisional ballot if they thought they had registered.

As it turns out, Zalusky was right.

All voters who said they were registered to vote in the state were eligible to cast a provisional ballot Tuesday, even if election judges at their polling place could not find their names on voter rolls. After Election Day, officials were to determine whether the provisional ballots are valid and should be counted.

The Calvert Board of Elections realized the mistake about 4 p.m. after meeting with a lawyer from the local Democratic Party. Mary DePelteau, a county elections official, said the office informed judges in all 21 precincts about the problem.

"We misinterpreted the law," DePelteau said. "We instructed the judges in error."

With four hours before the polls closed, election officials tried to reach potential voters who had been turned away. DePelteau said her office had the names of 21 people who might have been turned away from the polls in error.

"I'm looking through the phone books trying to find them," she said late Tuesday afternoon.

County sheriff's officers also tried to reach about 15 people on a list of voters Zalusky said had been incorrectly turned away from the polls. But several of the would-be voters could not be located, DePelteau said.

"This is an imperfect solution," Zalusky said.

Zalusky and Darlene M. Cocco, another poll watcher for the Democratic Party at Patuxent High School, said election judges also incorrectly told voters that they could not cast ballots if they showed up at the wrong precinct.

Cocco was asked to leave the polling site about 9 a.m. after she told voters that they could cast ballots at any precinct.

"Some of these people had already gone to two or three polling places and were being turned away again," she said. "It is very disheartening. My understanding is that we should encourage people to vote."

Dozens of Calvert County voters may have been disenfranchised this year, Cocco said.

"In the future," she said, "I would like to believe that elections would be done right."

Poll watcher John L. Zalusky says police escorted him from a Lusby polling site after he rightly questioned the withholding of some provisional ballots.