Firstly, I do dislike Tim Kennedy, as I have made clear many times, and my opinions on him should largely be ignored for that reason, just like the opinions of what I term his 'fanboys' should be ignored. However, him grabbing Romero's glove is a fact not an opinion, and I'm glad you acknowledge that.
If a foul is committed as a direct result of having received a foul, then I most certainly think the secondary foul can be described as being negated, although I accept that irrelevant is not the right word. If a fighter were to produce a small razor and stab his opponent, causing him to grab the cage in pain, I think it is safe to say that everyone would be in agreement that the cage grab should be ignored. The argument is not that one foul necessarily cancels out another - a deliberate groin shot in response to an eye poke is certainly not negated - but in an extraordinary situation like this, the secondary foul only occurred as a result of the initial foul and thus I don't see how much weight it can be given.
It is also entirely unclear whether Yoel did anything wrong at all for it to be considered a foul or even dirty. There was confusion regarding excess vaseline, that was not applied by Romero's corner, that caused much of the delay and the language barrier also contributed. Even if Romero and his corner knew exactly what they were doing, he was fortunate enough to have a legitimate reason given to him. Further, it is complete speculation that the extra recovery time contributed to Romero's victory. We have seen guys like Dan Henderson and Frankie Edgar recover from legit KOs in an instant, let alone rocked guys recovering in 60 seconds. It may have been crucial, it may not have been, we don't know.
My point is that we had a situation where a guy committed a foul and the only negative effects he suffered were that the guy he fouled was allowed an extra few seconds to recover due at least in part to a commission error, as opposed to the 5 minutes a guy can receive if was an illegal knee or groin strike. Say that out loud and realise how absurd it is. Guys who still go on about it clearly aren't capable of objective thought. Thus they are assigned a derogatory and dismissive term like 'fanboy'.