There's some vague theortetical similarities but important functional differences. There's way too many variables with fouls. With a drug test, it's often simple: test positive and your win gets stripped (yes, I know there are some more complicated exceptions).
But there is nothing simple about post-fight foul adjudication.
DC poked Stipe first. How do we know Stipe was unaffected? And the one round most people agree DC won came after the eye poke. How is clear that Stipe's win should be taken away? It's a minefield.
The ref is there to adjudicate in real time. Let him make the call. If he misses it, oh well.
