I too would bet on Boardman being clean. He was a TT specialist and not much cop at climbing. He made it clear his aim was the prologue TT's and abandoned / crashed out of most of his TdF tours. He was very open about his medical condition (osteoporosis) that required him to inject testosterone (which he refused to take until his career was finished). If you watch his performances in the prologues he gives everything and then appears for the next day's stage, still looking utterly knackered. Not the way we remember LA looking after his "recovery" techniques.