you can't fool yourself when you don't actually know the truth. You are just assuming they "must have taken something", it's just an assumption and I don't think its true.
they have in fact a dozen urine check and blood sample taken per day, some competitors are complaining being overly drained, so I really don't think you can take drugs and get away from it.
If people question Bolt's record they should question Phelps' too, until proven otherwise I believe these are genuine records.