If there are multiple addon users in the raid, normally the Master Looter will handle the priority lists.

If someone else sends import notifications, they could have manipulated imports without knowledge of the master looter.
Especially, prio tables created by whispers would be overwritten.

The master looter addon should not simply accept incoming priority updates, but present a request to the user to ask if this is ok, or if he in turn want to supersede with his currently list.