After a restore is complete, the homemdb and proxy address fields (among others) will show up correctly on the restored DC (Domain Controller) but these will change to incorrect values soon afterwards. You may also notice the mailbox in Exchange System Manager showing as disconnected.
Recovery Manager will first reanimate the tombstone and mandatory set of attributes. If these objects get replicated (first replication prompt) before linked attributes (second replication prompt) it is possible for them to be stamp incorrectly by a RUS (Recipient Update Service) running on a different DC. Once the RUS stamps these attributes on the remote DC (usually with incorrect info), it will replicate the updates back to the other DCs in the environment (including the DC that the objects was first restored to) since these attributes are now newer in AD. Please note that this is not an RMAD issue as such but occurs when replication causes a long delay between the reamination of objects in the forest and the writing of the linked attributes.