Tell the property manager she better have a valid reason for HER obtaining a personal restraining order against him, because if she interferes with your legal right to have guests come visit, you will sue for breach of contract under the principal that you are being denied the right to quiet enjoyment of your home.
Just be aware that this could put you on their 'crap list', so be very, very careful in having him stay overnight. They will be looking for the least little thing to evict you on.
Update: All of you would find yourselves on the losing end of a lawsuit. Management can deny tenancy to the ex-convict, and they did here. But they cannot ban someone who has not broken any law since being released from prison. Legal tenants are allowed to have visitors, including ex-convicts. An exception would be if the ex-con was a known sex offender that could not go anywhere there were children and the apartment complex was home to children.
Someone mentioned that the management might be afraid that the guy would try to become an illegal resident, having been denied. While that's a valid fear, there is a legal remedy to that if it is attempted, and that is eviction of the tenant that allows it. You can't ban someone that hasn't done anything just because you're afraid they MIGHT do something.
If you were the owner of properties that are exempt from Fair Housing Act rules, you can ban anyone you want for any reason. This property manager cannot.