they are just taking the responsibility off their shoulders now... like always, they did gave permission, bahria town did atleast. if they didnt, would they let this happen on their area? they have their own police which cud ve made the ppl ran away.not only did they allow it, they also provided guards, police, firetrucks and ambulances. if they hadnt, do u think the organizers wud ve spent huge sum of cash to get these things? not at all...
also keep in mind that events like these are also a way of promoting and marketing bahria town, so they let them happen.and the CEO, Ali raiz, is also fond of cars so he gives permission without a problem.