Danny Batth got the visitors off to a great start with a diving header after 10 minutes, but Nouha Dicko immediately scored an equaliser.
But Oliver threw Wolves a lifeline just before the hour mark with a controversial penalty decision, and Bakery Sako netted the spot-kick.
And Wanderers took full advantage, with James Henry running through the heart of the home defence after 64 minutes and firing past goalkeeper Adam Collin.
"There were three real penalty claims in the game," said Evans, "One after two minutes which I have just looked at again and it was a stonewall penalty.
"I have just looked at the Wolves penalty and it is not a hand ball, and then there was a challenge in the box on Claude Davies which again was not given.
"I was delighted with the effort and the energy, but it all changes when the referee gives Wolves a penalty. I am not questioning the integrity of Michael Oliver, but I think he has had a shocker. There were three big decisions and the big referees should get the big decisions right.
"There was no reaction from the Wolves players, the Wolves management or the Wolves supporters. Everyone in the Wolves scenario was as surprised as we were. I have just asked (Wolves boss) Kenny Jackett if we would have got that at Molyneux and his reaction was 'well I didn't give it'.
"At 3-1 Wolves were dead and buried, but would we have got that penalty at Molyneux - not a chance."