Giants receiver Golden Tate may indeed have been telling the truth when he explained that he began taking a fertility drug, that he realized in a matter of days that the drug is a banned substance under the PED policy, and that in the interim he was randomly tested under the PED policy. Like Tate, nearly every player who gets caught violating the PED policy has a plausible (or at least semi-plausible) excuse that softens the stigma of using PEDs for cheating.
Indeed, apart from receiver Julian Edelman (who didn’t bother to offer an excuse at all), every player who ever has tested positive for PEDs has had an explanation that didn’t involve using Performance Enhancing Drugs to actually enhance performance. Most often, the player took a supplement that unbeknownst to him contained PEDs. On other occasions, it was a fertility treatment.