No word over here in UK about what the positive is for. If it was something taken inadvertently surely the athlete would have come out and said so - not in order to be eligible for competition in the near future but to protect his reputation. Better to be regarded as a bit stupid than an intentional cheat!!
When will athletes learn? All these legal supplements that claim to massively boost performance are expensive junk ; they only have any effect if they contain small amounts of PEDs - which, of course, aren't listed in the table of contents!
(And what the hell is "muscle milk"? Is it that well known substance widely known as .... milk?)