Asked specifically whether he had ever had a TUE, Thomas replied: "No."
Widely regarded as one of the most humble and loyal riders in the peloton, Thomas' victory has been almost universally welcomed, even by the local fans who have made his and Team Sky's Tour so difficult this year.
A tiny smattering of boos broke out at the podium presentation but it was drowned out by cheering and clapping, nothing like the jeering Sky's riders have been subjected to at this race.
The dislike of Sky stems from multiple factors.
A general feeling of alienation with a race the British team has dominated since 2012 is almost certainly the biggest. But general scepticism arising from revelations regarding Sky's use of TUEs, particularly to help Sir Bradley Wiggins win that first Tour in 2012; plus the team's lack of transparency in the wake of the Jiffy bag scandal; the recent MPs' report; and the investigation into the culture of behaviours at British Cycling have not helped.
Thomas provides a potential antidote to that narrative.
Froome has been a strong advocate for a clean sport but his sudden emergence in 2011 meant he has always been the target for sceptics. And his recent salbutamol investigation gave them a stick with which to beat him, however unfairly.
Thomas has never applied for a TUE, is not asthmatic and does not use an inhaler. Even when he fractured his pelvis at the 2013 Tour, he says he took only Ibuprofen.
He also has an easy charm. Asked when he expected the achievement to sink in, Thomas smiled. "Maybe when I'm 70, sitting in the corner of a pub, telling some 18-year-old who I used to be."
This has been a breakthrough month in his career, which might sound odd for someone who has already won two Olympic golds. Thomas was in no doubt this was the biggest achievement of his career.
"Oh, for sure it's bigger," he said.
It will be fascinating to see how Sky divide up their grand tours next year, with Froome still contracted to the team until the end of 2020 and Thomas having agreed terms on a new multi-year deal.
Froome and Thomas could carve up the Giro d'Italia and the Tour, taking one each. But they will be 33 and 34 respectively in a year. Time is running out for Froome to get that record-equalling fifth Tour title, or for Thomas to become a multiple winner of cycling's biggest race.
Does he want another yellow jersey?
"I've certainly got the taste for it," he admitted. "This year, I've really enjoyed racing for stages and being aggressive; racing on instinct almost.
"It would be nice [to win more grand tours] but if I do nothing now for the rest of my career, I can be happy."
In the more immediate future, Thomas had been pencilled in to ride the Vuelta a Espana next month.
There is now talk that both he and Froome could ride the Tour of Britain, which would be a huge boost for that event.
Thomas may have to wait until his hangover subsides before making a decision.
That, ultimately, is Thomas' greatest gift. He is a normal guy who enjoys a beer and the rugby. And who has an incredible appetite for hard work.
"Just dream big," he concluded. "Go for it. There's nothing holding you back. You can have ups and downs but if you believe in something, keep the faith, keep fighting. And don't let people put you down."