Crossroads GPS, the dark-money nonprofit group co-founded by Karl Rove, recently unveiled a TV ad hammering North Dakota Democrat Heidi Heitkamp, a candidate for US Senate, for spending “taxpayer dollars to buy private planes.” That was a lie.

In a takedown letter sent to local broadcasters, Heitkamp explained that the planes referenced by Crossroads were given to her for free by the federal government. What’s more, the planes formerly belonged to the Department of Defense and one was for drug trafficking surveillance, the other for spare parts. No money was spent, and the planes weren’t for “private” use at all.

Crossroads responded by spiking the ad, which it had paid $191,000 to splash across the North Dakota airwaves. Crossroads spokesman Nate Hodson told the Huffington Post the ad was “was voluntarily removed from rotation” after realizing “a content issue.” The way Hodson put it, it appeared that Crossroads had owned up to its own error and worked to right a wrong.

Not quite. As Politico’s Maggie Haberman reported, one North Dakota broadcast station, KMXC, said it had alerted Crossroads to the ad’s inaccuracies well before the spot was pulled, undercutting Crossroads’ claim to have proactively pulled the ad.

Heitkamp, formerly North Dakota’s attorney general, faces Rep. Rick Berg (R-N.D.) in the race to replace outgoing Sen. Kent Conrad, a Democrat. Berg leads Heitkamp by 5 percentage points in RealClearPolitics’ polling average.