Except that doesn't look like X-ray effects at all. CT X-rays do not cause uniform damage to lengths of film. You get patterns, lines, squiggles. A small but detectable, uniform "fog" would not be from CT scanning.
Clearly the photo in that article shows a Security version CT scanner, and the writer of the article says his film did go thru.
“On that roll, I had already taken pictures but hadn’t developed it yet,” he tells PetaPixel. “[After developing it], I noticed that the shadows seemed a little grainier than I would have expected. Combine that with articles that claim ‘just one scan from the CT Scanner could destroy your unprocessed film,’ and I was too scared to ever make the same mistake again.”
"However, he later became curious about how much of an effect the CT scanners would have on film, and later returned to the airport specifically to further experiment.
“This time around, I wanted to control the experiment more. I sent one roll of Kodak Portra 400 that I had not yet taken pictures on through a TSA CT scanner at BWI airport,” Nuri says. “The roll only went through security one time and was not sent through the TSA CT scanner again after I shot the photos. I then loaded that roll into a 35mm camera with a 50mm lens and loaded a separate 35mm camera with a 50mm lens with a fresh, unharmed roll. I shot the exact same pictures using the same settings on both cameras for each shot so that I could compare them side-by-side as accurately as possible.”
Yes, CT causes patterned exposure artifacts. Just maybe the CT scanner does one single exposure (like an X-ray) or maybe 2 planar views, and if it detects something suspicious it then does the 3-D imaging pattern for its image and for explosives detection, in an effort to save time and do full CT only when necessarily, Speculative, on my part. But that may explain why there are a number of 'went thru CT...no damage seen' reports. CT is basically a higher dose form of X-ray