Instead, she pointed her finger at Hillary Clinton.
On Tuesday, Trump national spokeswoman Katrina Pierson had blamed Khan's death in Iraq on Obama and Clinton in an interview with CNN's Wolf Blitzer.
But she changed her story Wednesday in a lengthy exchange that amounted to a live fact-checking.
When asked by CNN's John Berman about her accusation that Obama and Clinton "probably cost (Khan) his life. You do acknowledge now that there you were just wrong."
"Well, absolutely. That's why I used 'probably,' because I was just going through the timeline," said Pierson, who then alleged that Trump was being blamed for Khan's death.
"But no one was blaming Donald Trump for Capt. Khan's death. You were blaming President Obama and he wasn't president yet," CNN's Alisyn Camerota said. In fact, the president was George W. Bush.
Pierson then dug in on her argument that Clinton was responsible for Khan's death, "No, I was talking about Hillary Clinton voting specifically for the war. That was during that time period."
Pierson's immersion in the Khan controversy began Tuesday evening, when she said Obama and Clinton were at fault for Humayun Khan's 2004 death. He was killed by suicide bombers in Iraq.
"It was under Barack Obama and Hillary Clinton that changed the rules of engagement that probably cost his life," Pierson told Blitzer
. "So I don't understand why it's so hard to understand why Donald Trump ... is being held responsible for something he had nothing to with while Hillary Clinton had everything to do with."
That accusation quickly drew a plea from Khizr Khan on CNN, "I would again appeal to his surrogates that please show some decency, refrain from what you're tempted out of anger and out of this ugly partisan-ness."
As she was confronted Wednesday about her statements, Pierson appeared to not know or understand how Trump had attacked Khizr Khan and his wife, Ghazala Khan.
"Well CNN has been talking about an attack on the family, so what exactly was the attack? So we can clear that up. What was the attack?" Pierson asked.
Berman explained that Trump had gone after Ghazala Khan by suggesting she was not allowed to speak at the Democratic Convention because of her religion.
Pierson then accused Khizr Khan of trying to undercut the Constitution with Sharia Law -- something which Khizr Khan has said is inaccurate.
"He was speaking specifically to the reports that the father, who is a strong proponent of Sharia Law. And actually writing about it and how the Constitution should be subordinate to Sharia Law," Pierson said.