35 minutes into the Premier League match, Cavani fired in from a tight angle after Paul Pogba had played him in.
But in the build-up to the goal, Scott McTominay caught Son with a hand to the face, which left the South Korean rolling on the ground in apparent pain.
The goal went to VAR, with referee Chris Kavanagh called over the pitch-side screen before ruling the goal out and awarding Spurs a free-kick.
After the decision, PGMOL, the body responsible for match officials in the English top-flight, released a statement explaining the decision.
“It wasn’t part of McTominay’s natural running movement and was careless,” it said.
But despite that explanation, Sky Sports pundit and former Manchester United captain Keane was left furious and blasted Son.
“I’m amazed really. If this is a foul we should all go home. It’s really bizarre. A player like Son to roll around like that it’s embarrassing,” he said in his half-time analysis on Sky Sports
“That can’t be a foul. How a player can stay down. And it’s not just Son, to be fair Rashford done it about 10 minutes earlier.
“Both sets of players rolling around, screaming. Referee’s under huge pressure. They’re doubting every decision they give now but clearly I think he’s got this wrong.”
Fellow pundit Micah Richards joined Keane in criticising the decision, also sharing his frustration at VAR.
“It’s embarrassing. This is not football anymore. I know we have a laugh and a joke and all that but this is spoiling our game,” Richards said.
“I can’t recognise the game anymore. If this is a foul, Roy’s right, we might as well as go home now. It’s an absolutely ridiculous decision. It’s spoiling football.”