Pulsars with accreting disk in binary system Following this line, I am wondering about the following question.

Accreting pulsars in binary systems are usually thought to accrete from a prograde disk, so increasing their spin in the process.

But why is the disk supposed to be prograde?
As far as I know all accretion disks are prograde. When the pulsar starts accreting mass from it's companion this mass is pulled to follow the pulsar's rotation.