I followed Andy the last 10 Years and I am pretty sure he isn't a doper.
I started to follow him during school time. He even wasn't able to cheat during class papers.
Andy was a nice pupil and still is a nice person, nowadays he is a bit arrogant due to the fact that he is overhyped in Lux.
He likes to go fishing, being out in the nature, hanging around in bars or just going to the pub and having a talk with the old people who discuss life in the pubs. So sometimes he is drunk, looses his driving license and ….
He is absolutely not interested in doping as when he would try, he is just unable not to tell nobody and it would come out immediately. He isn't even able to manage to dope.
Even Kim Andersen sometimes get's nervous with him as Andy isn't even able to prepare well for a race. Still he forget's to pack his bag properly or he forget's his bicycle or his wheel, his helmet … (It is a bit better now, not like in the Giro when he misses the start, still talking to the podium girls). Andersen has to check his preparation.
All this make's him symphatic, but he is a chaot and need to train during races, as otherwise he is not enough concentrated.
Andy has one biological advantage. He is able to recover very well after an race and that's why in the third tour week he has an advantage over the other riders.
I am quite sure that he is riding clean, he is just unable to dope (sorry Andy, but I believe he isn't clever enough to dope)