grandad wrote:
Legally, I don't think you have done anything wrong. Morally, pinching someones booked fare is the most hienous of crimes.

You are not to know the fare has pre-booked so you've done nothing wrong. However it is professional courteousy to allow the PH to take their booking once you realise the passenger has phoned beforehand, presuming they are prepared to swap vehicles. Remember that PH may be driving past one day whilst you're stuck with the bonnet up or getting the 5Hit kicked out of you, if you knowingly pinched their job they may just keep driving past with a big smile on their face rather than stop to help
I find that customers don't care that they are able to get a flag down rather than wait a few minutes for the cab they've phoned - all they want to do is get home, so it's not your fault. I also find that round here most (not all) HC will refuse the fare once you tell them it's a pre-booking.