Meanwhile, Killian's widow and son also have questioned the memos' authenticity.
Marjorie Connell told the Washington Post she was "livid" at CBS and described the records as "a farce."
Connell said her husband did not keep files and considered Bush "an excellent pilot."
"I don't think there were any documents," she said. "He was not a paper person."
A CBS reporter contacted her briefly before Wednesday night's broadcasts, she said, but did not ask her to authenticate the records, according to the Post.
Gary Killian, who served in the Guard with his father, said a memo signed by his father appeared legitimate but he doubted his father wrote another that referred to the performance review.
"I am upset because I think it is a mixture of truth and fiction here," Killian told the AP.
The wire service said another officer who served with Killian and a document expert also said the documents appear to be forgeries.
Internet origins
The White House distributed copies of the memos, apparently dampening speculation they are fraudulent. But the copies are from faxes sent by CBS News yesterday.
Major news outlets such as ABC News and the Washington Post now are advancing the story, but it came to life through the scrutiny of weblogs such as Powerline and Little Green Footballs.
National Review's "Kerry Spot" weblog cited Bruce Webster, an expert witness in U.S. District Court cases on computer document forensics, who said the memo posted online by CBS News "has all sorts of problems" and points out the "typefaces weren't available on typewriters in 1973."
A Powerline reader said the document appears to use the superscript 'th,' but there "are no keys on any typewriter in common use in 1973 which could produce a tiny "th." The forger got careless after creating the August 1, 1972 document and slipped up big-time."
A number of Web contributors said they could create an exact representation of the document using Microsoft Word.
The author of Little Green Footballs wrote: "I opened Microsoft Word, set the font to Microsoft's Times New Roman, tabbed over to the default tab stop to enter the date '18 August 1973,' then typed the rest of the document purportedly from the personal records of the late Lieutenant Colonel Jerry B. Killian. And my Microsoft Word version, typed in 2004, is an exact match for the documents trumpeted by CBS News as 'authentic.'"
Others pointed out the memo did not have letterhead and the paper size should be 8x10.5 rather than 8.5x11.
According to the weblog INDC Journal, Dr. Philip Bouffard, touted as one of the top two experts in forensic document examination of typefaces in the country, said he cannot make a 100-percent-positive evaluation because the documents appear to have been copied several times.
But he stated, "It's just possible that this might be a Times Roman font, which means that it would have been created on a computer. It's very possible that someone decided to create this document on a computer ... . I've run across this situation before ... my gut is this could just well be a fabrication."
Bouffard noted the document has "proportional spacing," which was on only seven or eight models not widely available in 1972-73.
He also pointed out the number 4 does not have a "foot" and has a "closed top," which is indicative of Times New Roman, a font exclusive to modern computer word processing programs.
Bouffard told INDC Journal that after further analysis, he's fairly certain the Aug. 18, 1973, document is a fake.
He noted, examining his old papers, the inconsistency of the "4" coming up several previous times with forgeries that attempt to duplicate old proportional spaced documents with a computer word processor.
He said he didn't know who CBS contacted to verify the document's authenticity, but is aware of only one person aside from himself who might be more qualified to determine authentic typefaces.
'Previously unseen'
"60 Minutes II" reported last night it had "previously unseen documents" from Killian's personal office file.
In a memo dated May 1972, Killian writes that Lt. Bush called him to talk about "how he can get out of coming to drill from now through November."
The docment says Lt. Bush told his commander "he is working on a campaign in Alabama ... and may not have time to take his physical." Killian adds that he thinks Bush has gone over his head, and is "talking to someone upstairs."
One of the Killian memos is an official order to Bush to report for a physical, which never was carried out.
CBS says, in an Aug. 1, 1972, memo Killian wrote, "On this date I ordered that 1st Lt. Bush be suspended from flight status due to failure to perform to USAF/TexANG standards and failure to meet annual physical examination ... as ordered."
A memo from Aug. 18, 1973, according to CBS, has Killian saying Col. Buck Staudt, head of the Texas Air National Guard, is putting on pressure to "sugar coat" the evaluation of Lt. Bush.
The memo continues, with Killian saying, "I'm having trouble running interference and doing my job."
CBS News said Staudt, a Bush family supporter, would not agree to an interview request.
Bush spokesman Dan Bartlett responded to CBS's request for comment about Killian's statements in the memos.
"For anybody to try to interpret or presume they know what somebody who is now dead was thinking in any of these memos, I think is very difficult to do," he said.
Bartlett added that Bush's superiors granted permission to train in Alabama in a non-flying status and that "many of the documents you have here affirm just that."
CBS News noted that earlier in his flying career, Bush received glowing evaluations from Killian, who called him an "exceptionally fine young officer and pilot" who "performed in an outstanding manner."
According to military documents released this week, Bush scored 88 on an airmanship test, 98 on aviation physiology and 100 on navigational abilities.