The official on Monday wasn't as biased as some of those here and Monday are expressing. I also wondered why he didn't caution their FB in the 8th minute when he pulled Powell back. Maybe it was in the "too early" category, which I don't agree with, they'll get it from me in the 1st or the 90th if they deserve it.
I hear crowds shouting down referee decisions all the time and it 'can' have an effect but you never know which way, either for an easier time or to be stubborn against the 'abuse' but all within the interpretation of the Laws. The majority of the time it has little effect.
As GPC has said, the first lesson of refereeing is understanding that all players are cheats, whether it be appealing for a throw they know isn't or diving in the box.
But there are those who try to influence the decisions that they know have been made correctly, I do it all the time from my seat in the stands when I'm wearing claret, and there are those that shout the abuse/influence convinced that the official has got it wrong when in fact their version of the Laws are different to what is in the book.
If you are going to criticise the official, ensure that you know the Laws and the accepted interpretations first, that helps the blood pressure.
The Pompey official was different, it was only his second game in L1 this season and in front of over 18k he appeared to struggle with his confidence, he will have had better games but that probably wasn't one of them, all referees have them. He'll know that himself, but you could never accuse him of bias, he wasn't particularly good for both teams.