No, McCain instead seems to have repeated this nonsense multiple times. MSNBC notes:
Mr. McCain said several times in his visit to Jordan — in a news conference and in a radio interview — that he was concerned that Iran was training Al Qaeda in Iraq...
Mr. McCain said at a news conference in Amman that he continued to be concerned about Iranians “taking Al Qaeda into Iran, training them and sending them back.” Asked about that statement, Mr. McCain said: “Well, it’s common knowledge and has been reported in the media that Al Qaeda is going back into Iran and receiving training and are coming back into Iraq from Iran. That’s well known. And it’s unfortunate.”
It was not until he got a quiet word of correction in his ear from Senator Joseph I. Lieberman of Connecticut, who was traveling with Mr. McCain as part of a Congressional delegation on a nearly weeklong trip, that Mr. McCain corrected himself.
“I’m sorry,” Mr. McCain said, “the Iranians are training extremists, not Al Qaeda.”
The Democrats noted that Mr. McCain, Republican of Arizona, had made similar comments about Iran training Al Qaeda in an interview with “The Hugh Hewitt Show,” a radio program he called from Amman. “As you know, there are Al Qaeda operatives that are taken back into Iran, given training as leaders, and they’re moving back into Iraq,” Mr. McCain said, according to a transcript posted on the show’s Web site.
You can listen to McCain on Hewitt's show here, and watch a clip of McCain saying Iran is assisting Al Qaeda here.
So what's McCain's deal here? We know he's wrong on this, and he quickly flip-flopped after Lieberman corrected him. So I think that means that we can rule out that he was deliberately lying. But he repeated it multiple times, so it obviously wasn't just some slip of the tongue. So what's going on here? Speculate in comments.