Tunneruk has set the scene.
A crowded motorcycle bay in Central London, probably with a downhill camber by the rear wheel to allow drainage. Loud revving, up she goes.... Whoa! Down she comes, sideways. I hope he leaves a nice note giving his insurance details to the bikes on either side that he's demolished.
It strikes me that if he has enough room to slide in, climb on and ride it out off the main stand, there's probably enough room to stand alongside and rock it off its main stand as normal, though it is less exciting.
Sensibly, the stand at the front push-pull method is probably easiest and a lot less noisy.
Fella, you're working on the assumption that the bike will be crammed into a parking bay in central London. If the bike is parked in this scenario then of course it's highly likely to end in disaster!
I never once parked my bike in central London ........ I did however park it on the path along my lawn and had to fill a cylinder sized indentation in my lawn with top soil after one unsuccessful attempt!
If I had another 12 (which'll never happen) I'd continue to use this method, but only when it's realistic to do so!