Commissioners said they were offended by her comments, and Feibush's lawyer, Carl Primavera, called it a "heavy-handed" maneuver by the administration. Feibush is calling for her to be fired.
Markman, who declined to comment, apologized in a letter to the commission hours after the meeting, saying she didn't mean to imply it was acting improperly.
Nutter spokesman Mark McDonald said she was not sent to the meeting by the mayor but has the right "to look into anything within the executive branch, any transactions, any activity. That is her charge."
"She is a smart lady, a tough lady, a former assistant U.S. attorney who prosecuted municipal corruption," McDonald said. "Like all of us, she'll make a mistake from time to time."
At issue was Feibush's OCF Coffee House, which is in a historically protected building at 21st Street and Fairmount Avenue. The first-floor exterior of the building was illegally altered when he built the cafe, and he applied for "legalization" of those changes in December. The commission rejected that request but has since worked out a deal with Feibush in which he will make alterations to the exterior and get approval.
Markman, having watched the board reject first-time legalization applications from several homeowners earlier in the meeting, spoke up and appeared to be questioning whether Feibush was getting special consideration.
"So you are insinuating that that process wasn't followed here?" Chairman Sam Sherman asked her at the meeting.
"No, that's not what I'm insinuating at all," she said.
"That's exactly what you're doing," Sherman said.
The board voted unanimously to approve the application.
Feibush, who makes headlines for skirmishes with the city, said his cause may have been unintentionally aided by Markman because her words so enraged the commissioners. Despite the good result, he wants her axed.
"It's offensive as a taxpaying citizen that of all the corruption, of all the fraud in Philadelphia, our chief integrity officer decided to take time out of her day to spend two hours fighting windows that the Historical Commission then approved unanimously," he said in an interview.
Markman lives two blocks away from the coffeehouse and told the commissioners that although she learned about the meeting through a neighborhood bulletin, she attended in her "city capacity." She said she goes to the cafe and likes the coffee.
On Twitter: @SeanWalshDN