The analogy to Bonds is bollocks. Millar fessed up to doping, served his time, and now is saying "don't do what I did." Bonds admits to nothing, even though almost all evidence points to his involvement with BALCO.
So Millar has every right to say what he does - and he has a more unique perspective than many pro riders can admit to having.
These days, if you're a UCI Pro Tour rider there's an expectation to play by the rules: report your whereabouts, play clean. Rasmussen may be an introvert, but that's no excuse for not calling the Danish Cycling Federation and reporting his Mexican vacation. He's a Pro Tour rider, and he's not above the rules.