Milligan posted an update on Tuesday, claiming airport staff reviewed CCTV footage of her going through security and agreed "guards didn't give customer service/decency they expect when made me remove fitted jacket and go through in camisole."
The journalist said Sydney Airport apologised to her and agreed she should have been given an option to "modestly pass through" and speak to female security.
According to Milligan, the airport sent her a statement reading: "The correct protocols for the new body scanner were followed by our security contractor, but there was clearly a shortfall in terms of our expectations around customer service and communication."
"So it's up to government to change jacket rule," Milligan remarked.
Other flyers said they had encountered similar situations after Milligan's tweet, including a woman who claimed she was ordered to remove a pocketless cotton shirt while wearing only a camisole and bra.
Milligan said she was asked to remove her business jacket since the "new full-body scanner" was unable to screen her properly.
"But it could scan the old guy in the bulky, loose jumper in front of me?" she tweeted. "Complete nonsense. I said that and they just ignored me. It was gross."
The "private" security staff was all male, Milligan said, adding that even asked when the man in front of her wasn't ordered to remove his oversized coat.
"I did and they stared ahead like drones," she tweeted. "Apparently it's only fitted blazers over small camisoles that make the machines go crazy."
The Project host Lisa Wilkinson shared her own "uncomfortable, inappropriate" experience on Twitter hours after Milligan.
"At Brisbane Airport and Adelaide Airport the scan showed up the underwire in my bra and zip on my jeans and I had to have a full pat-down in both areas," Wilkinson tweeted. "Embarrassing, uncomfortable, inappropriate and should be fixed."
Some on Twitter accused Milligan of "grandstanding" and said that she could've requested a private screening area, while others cited the airport's passenger screening protocols that requires flyers to remove "bulky" coats and clothing.
"Security [seems] to be giving a pass to men with bulky jackets, yet a fitted jacket for women an issue," one reply read.
Milligan, meanwhile, shot back that she was asked to remove her business jacket because it was "too loose" – further complicating matters.
"It's not loose," she tweeted. "It's fitted. I pointed out the loose, bulky jumper and they had nothing."
Others claimed outsourced security staffers at airports were to blame.
"You forego in-house control of higher standards," one critic noted. "This is a violation of aviation security standards. Next time I fly I'm going to wear an adult diaper with a furry tail and a steel bra."
