TBH, even if he was clean (which I don't believe is the case), its good that he's getting banned. If it's your JOB to provide accurate whereabouts information, be there for your window, follow the procedures, etc., and you can't manage to do it 3 separate times, you don't deserve to be called a professional.
If there genuinely is a case where the doping agency screws up and gives you an undeserved strike, wouldn't you want to address that BEFORE you manage to get another one and get yourself banned? Like, if I got a second strike for a reason I thought was undeserved, I would at least contact the doping agency and try to reason with them to get that strike removed. I might also want to publicize the mistake the agency made, just to show that there are, in fact, cases where the agency screws up. Why would you try to contest a "screwed up" 2nd strike AFTER you've already gotten the third and a ban? Super suspicious and frankly he's showing his hand by making this argument.