No matter what Spurs did against us . Arsenal's 1-0 victory over the Mags meant Tottenham had to settle for a fifth-place finish.
Had Marriner awarded Villas-Boas' team a penalty in the first half, the Portuguese thinks it could have been Spurs, and not Arsenal, who finished in fourth, however.
In the 21st minute with the score 0-0 at both grounds, Bale entered the Sunderland box and went down after colliding with Sebastian Larsson.
The Swede used both arms to knock the 23-year-old to the ground, but rather than award Spurs a penalty, Marriner handed Bale his fifth yellow card of the season for simulation.
Andre Villas-Boas: "I don't want to put the spotlight on the referee, but I think it (was) absolutely decisive.
"Apart from the distance that separates the grounds, the emotions are felt very strongly. It would have certainly been felt at Newcastle, and it would certainly change the running of this game too.
"Sunderland would have to be more adventurous, and so there would be more space.
"It was extremely disappointing decision in my opinion for the fact that Andre was on the conference at start of season and we spoke about Gareth's incidents.
"It was a poor decision. It could have potentially changed the nature of other game too.
"It's very, very unusual that we didn't make it.
"If you look at past seasons with that number of points you would normally achieve it.
"It's difficult for me. Obviously we would ideally have achieved that fourth spot, we certainly did enough to deserve it, but we didn't in the end."