Should not matter if it is a tainted supplement...The fighters are responsible for what they put in their bodies..Ignorance should not be an excuse.
Can you understand what "tainted" mean?
By your reasoning I would guess not.
"I didn't read the ingridients of that medicine", said the defense of NOBODY EVER.
There's a thing called cross contamination, where you can't use the same machine that packed X drug to pack Y drug. Manufacturers are supposed to keep this from happening, but not just it costs a lot of money, you also have to check whether what you do against contamination is doing well or need more effort. Since there's little to no checking, they basically have to decide whether they want to make more money or less money. Tough call...
Manufacturers might get sued in US (they won't) but in Brazil I can assure you there's no such thing as authorities are all bribed on a regular basis.
Odds are that a small but clinically detectable amount of X medicine will appear on various Y's units, small enough to be inert to the human body. And not just UFC banned stuff, a bunch of other things, that's one of the reasons why people despise so hard on the whole homeopathy paradigm. It's like getting pissed that a bug's fragment can be found on your Cup Noodles. It's right there, you just need a microscope.
UFC won't pay fighters to pay private labs to scrutinize each aspirin or antibiotic they take, and if you don't take your pills and get sick a week prior fighting then Sherdog (aka Trollersville) will immediately start bashing you as if you're ducking the other guy, even if you already won against him in the past.
I know that people cheat, we can see that. Take a look at Lesnar, (the old) Overeem, GSP, TRT Belfort or Northcutt, these are all guys who I can understand people's suspicions, not JDS.
But then, I can cope that I'm being naive. It's just that if JDS was taking PEDs he has to be the laziest PED abuser in history, as his PEDs are not changing much.
IL;DR- There's simply no way to deal with trolls.