There was more contact between Doherty and Forster than either tackle Salisu got booked for, and they were both correct.
I don't agree with there being more contact, but, hypothetically speaking, if there was more contact, then the difference is that it wasn't unfair contact. Football is a contact sport. The only time contact is deemed unfair is when it has prevented a player from continuing the move, usually deliberate. In this case, the keeper jumped into Doherty's back. Doherty has done absolutely nothing. He didn't even commit to the jump. The keeper, under no pressure from Doherty failed to catch the ball, dropped it, then kicked it in his own net. How neither the bent ref nor the bent cunts in the VAR box felt the need to really take a long hard look at that is beyond me. The fact they didn't tells me all I need to know - they were looking for chances to disallow goals.
Offsides in general are clear and obvious. They draw the two lines and then its clear if its offside or not because we can see the two lines. Just like goalline technology, even the smallest fraction of the ball is still on the line , its clear and obvious that the ball hasnt crossed.
You cant do that with a foul which might be determined if someone used enough force to push someone . You cant measure that , so those kind of decisions are not clear and obvious.
Offside isn't yes or no Especially with replays being used. In this case, we can't even see what part of Kane they're claiming is offside. Worse still, is there is no way they can free the frame on the video at the exact point that the ball was kicked. They just can't do it. So when a player is millimetres on or offside, there's too much room for error as to when the ball was kicked to say for sure either way.
In those cases, you HAVE to default to the eyes on the ground and call it as it was. This should take as long as it takes for the keeper to pick the ball out of the net.