Here is a picture of a car, the black one, which was given a parking ticket for obstructing a crossover ( lowered kerb ). This car is outside the CPZ but just so you know the whole of Barnet is what is called a Special Enforcement Area and so you should never park across a dropped kerb ( except outside a CPZ and with the permission of the householder ).
It is clear that the car is not obstructing the crossover as a crossover is defined as starting where the level of the footway is lowered to meet the level of the road. That means that if your car ends alongside the sloping stone which takes the path down to meet the road then no contravention has occurred.
What I want like to have, to help my friend with his appeal, is photographs of cars which were similarly parked and where the PCN ticket ( Penalty Charge Notice ) was cancelled upon appeal. I would also need to have the PCN reference number if you are happy for your case to be used in support of my friend.
Even better if you have taken your case all the way to Patas as that will have set out the guidelines.
I do hope that you can help.