That's not really the point, is it? Obviously fans want their team to get a penalty. The argument is, without looking through a United (or anti-United) lens, should that be considered a dive? Fabianski pulled out of a tackle like a defender can. What right that gives for Rashford to fall over I don't know.
And Rashford took evasive action like any other player can and will when they anticipate a tackle.
Do you seriously think it would have turned Fabianski's lunge from not being a foul into being a foul if Rashford had jumped towards him instead of away from him? You're basically arguing that the actions of the attacking player is what determines whether the defending player commits a foul.
And ultimately anywhere else on the pitch a referee can and will give a free kick if a player makes a rash challenge, even if they try to pull out of it and don't make any contact. If the challenge is deemed to have been made in an attempt to prevent the opponent playing the ball then it's still a foul, penalised by an indirect free kick.


