Questioncan any damage accure by pulling an awd truck up on a flatbed towtruck while its in reverse?
Answerhighly doubt that any damage would happen but stranger things have happened...
There is give in the vehicle and most likely the tires would slide more than really bite and hold.
And there are other tricks to do this, such as using skates, go jacks, and even oil or dishwashing soap.
Must be more to this question than what you asked.