PSG won the first-leg of their semifinal 5-4 at the Parc des Princes in a thrilling contest.
One of the flashpoints was a penalty awarded to PSG for hand-ball against Alphonso Davies. The spotkick was awarded after referee Sandro Schaerer watched several replays of the incident on the pitchside monitor.
Former England captain Alan Shearer said on Amazon Prime: "Once I see that deflection on his arm, then that for me, shouldn't be a penalty. I don't agree with that, I really don't agree with it.
"Once it comes off his leg onto his arm, then for me, that's a different story.
"If it hits his arm, okay, I might accept. But once it comes off a different part of his body and onto his arm, what's he meant to do?
"I think the handballs are nonsense. I think they've tied themselves up in knots over the years trying to get somewhere, which is fair. And I don't think that is, but there you go."
Manchester United legend Wayne Rooney agreed, adding: "I don't think it's a penalty. His hands are behind his back and moves out when the cross comes in but it comes off his right thigh and then on to his arm.
"Maybe it's a bit different in Europe, I don't know, but not a pen for me."