State House lawmakers have apparently accidentally legalized fracking in North Carolina, due to a deciding vote one Democrat says was a mistake.

Rep. Becky Carney, D-Mecklenburg, says she did not intend to cast the key vote that overrode the governor's veto of the bill.

The vote was 72-47, exactly the number needed for an override. Without Carney's vote, the veto would have been sustained.

Carney characterized her vote as "very accidental."

"It is late. Here we are rushing to make these kind of decisions this time of night," she said.

Carney pointed out that she has voted against fracking in the past, and said she spent the day lobbying other Democrats to uphold the veto of Senate Bill 820.

"And then I push the green button," she said.

Just after the vote, Carney's voice could be heard on her microphone, saying "Oh my gosh. I pushed green."

Carney said she turned her light on, but Speaker Thom Tillis would not recognize her, so she went to the front to speak to him.

"I made a mistake, and I tried to get recognized to change it, as people have been doing all night on other bills, and it was too late," Carney said. "Because it would have changed the outcome of the vote."

Under House rules, members can change their vote if they've made a mistake - unless the change would affect the bill's passage.

"I feel rotten, and I feel tired," Carney said. "And I feel that mistakes are made constantly when people are tired. And I feel rotten about it, but I take responsibility for my vote."

As soon as the vote was cast, House Minority Leader Paul Stam used a procedural move called a "clincher" to ensure the veto override could not be reconsidered.

Other House Democrats who voted for the override were Reps. Kelly Alexander and Rodney Moore, Mecklenburg; Rep. Bill Brisson, Bladen; Rep. Dewey Hill, Columbus; and Rep. Suzi Hamilton, New Hanover.

The Senate had overridden the veto on the fracking bill earlier Monday. The measure is now law.