That is awful. And really unlikely breed to bite. But then any dog that is in pain or has been abused can turn.
Jeff bit 3 people. 2 were my dog walkers (both ladies), but I figured out it was the pain meds he was on that turned him a bit crazy. We got new drugs after 8 days. Both ladies forgave him, thank god.
The other one was a man. Jeff had got caught up in his lead in the back of my car, and I couldn't free him, it was really tight around his neck. I panicked and started yelling if anyone had a knife. I guy ran across the road from the little cafe with a sharp knife, handed it to the binman who was trying to work the lead off the car seat headrest. He cut the lead. Jeff, panicked by my screaming and the strange man in the back of the car with him, bit him on the ankle. I got in the car and drove away as fast as possible
I never ever worried that he would bite me though.
The first weekend at home when he met my parents for the first time, he did try and push my Dad around quite a bit. But I got him by the scruff of the neck, and marched him outside, and put him in a time out for 20 mins. (Jeff, not my Dad!!) Never did it again. And was always very very gentle around my Mum. The only time he would walk by someone's side, was when my Mum had hold of the lead.
Foxy - you did the right thing though. You couldn't have given him back to rehomed again. And you couldn't trust him again. It was the only option. Such a shame those involved in the rehoming process weren't honest, because it is possible to find good, loving homes for problem dogs. It's just harder.