Public Housing Voucher's?

I have a friend that has a Voucher through Public Housing. His lease is not yet up but needs to move to another location because of medical reasons.. His current Landlord says it is fine if he breaks the lease because of his medical issues. But his Coordinator states she will not allow him to break his lease. She states she is in charge and will drop him from the program if he pushes the issue. What can he do????