Honestly mate, I do appreciate we are Spurs fans, but you need to take off your Lilywhite tinted glasses. Lamela was never in control of the ball and in fact what I see is him running into Van Dijks leg who is pretty much trying to withdraw from the effort to make contact with the ball. Lamela is actually moving away from the ball.
On the other hand, as unlucky as Serge was, he actively swings his foot into Mané's calf, and he was actually moving toward the ball at least making an effort to garner control of it.