Initially I wouldn't have said he was, TDO is pretty one-dimensional in his approach.
The more I think about it, the tap and run approach is more suited to Amir's flaws, the problem is when he starts standing his ground and gunslinging with the right hands.
If Khan stuck to the one-two, with the left to the body mixed in here and there and skipping out of range he'd be fine.
It's when he tries fighting like Pacquiao that he runs into bother and unravels, either by getting sparked or fouling/pushing/rabbit punching etc.