Follow this, if you can: An Army helicopter pilot who yesterday told CNN that he flew the helicopter carrying NBC News’s Brian Williams in Iraq in 2003 and sustained small-arms fire during the mission is now doubting his own remarks, a development that re-magnifies embellishments made by the now-anchor of “NBC Nightly News” and stains CNN’s reporting through the distortions of battlefield memory.

Now to unpack. As reported yesterday by CNN’s Brian Stelter and “The Lead” with Jake Tapper, Rich Krell, who claimed to be piloting the Chinook helicopter on which Williams was flying, said that his helicopter had sustained small-arms fire, along with other helicopters in the March 2003 mission to transport materials in support of the U.S. invasion of Iraq.

“We took small-arms fire. All I know is one RPG was fired. It struck the lead aircraft, which was what we call six rotor discs in front of me,” said Krell.

Those remarks provided great succor to Williams, for one key reason: He was under heavy criticism for claiming to have ridden in a helicopter that had taken both small-arms and RPG fire — claims that he made in a March 2013 appearance on David Letterman’s “Late Show,” among other venues. If Krell was right, then Williams may have told a false story only about the RPG fire, not the small-arms fire. Perhaps the backlash against him would have quieted.

Hold on, though: Krell, according to Stelter, has begun “questioning” his “memories.” Which means that he’s bailing.

The upshot spells renewed trouble for Williams and a minor bruise for CNN. Whereas it appeared there for a moment that Williams was guilty of a far smaller story-enlargement than before, the recent flip-flopping exposes just how expansive was his so-called “mistake” or “conflation,” depending on your euphemistic preference: Either he lied about the whole thing, or his “mistake” was driven by a depraved need to lump himself with heroism. Neither is a good trait for a newsman.

As for CNN, Stelter has responded to the change-in-story by posting updates noting the pilot’s foggy memory. “The information I gave you was true based on my memories, but at this point I am questioning my memories that I may have forgotten or left something out,” Krell told Stelter in a message. It bears noting that Krell was indeed piloting one of the helicopters on the mission that day. Just not the one, according to reports, that was carrying Williams.

NBC News has been silent on this crisis since Williams apologized on Wednesday night for having mischaracterized his Iraq adventures in a broadcast last week, in which he gave tribute to a service member who had helped protect him and his camera crew after landing in the Iraqi desert following the aborted helicopter mission. “The helicopter we were traveling in was forced down after being hit by an RPG,” Williams said in the broadcast.