"I was at the World Champion- ships in Berlin with Wada [the World Anti-Doping Agency] a couple of years ago," he says. "The IAAF wanted to speak to me privately about athletics being so far behind cycling in anti-doping. They wanted my advice. I got in a lift and there they were – Dwain and Paula! They didn't recognise me. They were there as athletes, in their kit, and I was there in a suit with my Wada accreditation around my neck."
Like Chambers, Millar, banned for doping for two years in 2004, has grown used to the "drug cheat" headlines. There were more of them last week, when Team GB selected him for the Olympic road race squad on the same day that the latest pursuit of Lance Armstrong, now charged by USADA with doping offences, gathered pace.
While Armstrong – not for the first time – screamed "witch-hunt", Millar kept a low profile. That is because if all goes to plan, Millar will captain the five-man British road race team, bidding to lead Mark Cavendish to Olympic gold.
Millar's rehabilitation feels almost, but not quite, complete. He is one of the architects of the Garmin team, a Wada committee member and the author of an acclaimed and some say, redemptive, autobiography, "Racing Through The Dark".
There have also been the numerous outspoken interviews and contrite confessions, which have fuelled a growing reputation for honesty and candour in the media.
Yet the final unlocking of the gateway to redemption came when Team GB's performance director, Dave Brailsford, present when Millar was arrested by the French drugs squad in 2004, picked the Scot for the Olympic road race.
Among those who have criticised the lifting of the BOA's lifetime ban is Sir Chris Hoy. On Wednesday, however, Hoy found himself sitting alongside Brailsford in front of the media re-iterating that position while also confirming he would welcome Millar into the team.
Millar, the influential team captain for Team GB when Cavendish won the World Road Race title last autumn, says he and Brailsford had already discussed the potential impact of his selection on other team members.
"I spoke to Brailsford about whether they wanted me there or not," he says. "He was honest with me and told me that my selection would take into consideration all the factors, that if some team members were uncomfortable, if it would be easier if I wasn't there, then I'd accept that with good grace.
"The people who know about me know there's a lot more behind the drug cheat. I'd like to think that if people have an opinion, they know the full story before they judge me."
Even so, Millar has spent the past six months deciding what he would do in the event of the BOA's lifetime ban being lifted, knowing that if it was overturned, his past misdemeanours would be dredged up once more.
"It was an agonising deliberation for a month or so," he says. "I had many discussions with family and friends and it ended up being a very rational breakdown of the options and outcomes. I realised that it was probably up to me to proactively remove myself from selection, which seemed a bit of a stand in itself. I also felt it made a nonsense of everything I've been through and of arguing for a second chance if I then spurned it. It would have been hypocritical of me to do that. In a way it's my duty to put myself forward now."
Some of that angst eased when he and BOA chairman Lord Moynihan came face to face at a pre-Olympic media drinks party last winter. As the room fell silent, Millar and Moynihan shook hands and struck up an unlikely rapport.
Once the BOA lifetime ban was overturned, Millar initiated contact again. "I said to Lord Moynihan, 'Look – if I'm going to be a burden to the team and if the BOA are uncomfortable, and make what should be a positive experience negative, then I will step down. But he was very gracious. He told me that 'It will be over my dead body that anybody within the BOA will question your eligibility'. He was very straight about that."
Millar says Moynihan knows of his history. "He still stands by a ban, and I agree with that. But I still don't think a first-time offender should be given a lifetime ban. I don't think you can judge an 18-year-old new professional in the same way you can judge a 32-year-old millionaire athlete if they both were caught doing the same thing. Maybe in that case it's a lifetime ban for the 32-year-old, but for the 18-year-old it's four years or one Olympic cycle; I'd argue he deserves a second chance," Millar says. "Not every case is the same, the circumstances are different."
Perhaps too, following the relaxation of the lifetime ban, an issue that was once depicted very much as black and white is now being revisited and seen as grey, at least in Millar's case. "I became aware that maybe the tide had turned, that perhaps there wouldn't be the level of vilification we feared," Millar says. "It seemed possible that maybe my wife and my mum weren't going to have to read quite as much scathing pieces as we imagined."
In the end, he says, it was best to leave it to the selectors. "I'd understand if I ticked the boxes on a sporting level, but that because of the media attention and the disruption to the team, they felt they couldn't take me. I'd respect that. That way I'd have no regrets. But one of the worst-case scenarios would have been watching the Olympic road race on TV and then watching Team GB's hopes fall apart because I wasn't there to help and realising I'd been selfish to rule myself out."
Ultimately, given his experience, intelligence and knowledge of racing – along with his role in Cavendish's world title victory – Brailsford will be hard pressed to leave the 35-year-old out of the starting line-up on July 28.
"There isn't really anybody else with the experience of being team captain," Millar said, pointing to the unique characteristics of the Olympic road race. "It's a smaller peloton, five-man teams, all the best riders in the world at the peak of their condition – and the whole race is out to drop Cav. So, yes, it's going to be one of the hardest things we've ever done."
The focal point, Millar says, will be the circuits of Box Hill in Surrey. "It's going to be kicking off every time we go up that hill. It's going to be savage, because of the format and the smaller numbers of riders in each team. It's going to be a massive challenge for us and really hard to manage. It's going to really hurt."
Now Millar has to wait and steel himself for the final cut later this month, just as the Tour de France begins. These days, the Scot is totally accepted, perhaps even admired, by many within his own sport. None of his team-mates have any problems with him or his past; in fact, some of his peers may well wish they had been set free to tell their own tales with such honesty and authenticity.
"I was able to come back because I was able to help change the sport and," he says, "because my sport wants to change."
The Olympics are different, however, and for all Millar's qualities, he knows some of his compatriots may still have strong reservations over his inclusion.
"The irony is that I'll never set foot in the Olympic village," he says. "I'll be in a holding camp in Surrey and then as soon as I finish, I'll be heading off to the next race. I'm not going there for the Olympic experience; I'm there to do a job for the team and for Cav."