United came from behind to win in London, earning their 28th point of the season from a losing position as Spurs again let a lead slip.
After a lengthy process, VAR advised referee Chris Kavanagh to take a look at Scott McTominay’s challenge on Heung-min Son on the pitchside monitor and he ruled that the Scot, whose arm went into the Spurs player’s face, had committed a foul.
Asked about Edinson Cavani's opener, Mourinho told Sky Sports: "My opinion was we didn't deserve this result at all.
"We were unlucky because maybe Pogba should get a red card for an elbow on Serge Aurier."
Pushed on the Cavani goal, Mourinho said: "I don't know anything any more. I watched Fulham versus Wolves. I don't understand anything any more.
"Sometimes you get, sometimes you don't get. I don't know how to comment. You don't celebrate a goal because you are afraid."
Mourinho, who now has to be fighting for his job at Tottenham after this defeat leaves their hopes of Champions League qualification in tatters.
He added: "We needed points from the game and we didn't get them."