Dominate Person states the following:
Each time the target takes damage, it makes a new Wisdom saving throw against the spell. If the saving throw succeeds, the spell ends.
As written, this would presumably include damage from an ally - am I right?
From a gameplay perspective, this is a great boon to players who lose a team member to a vampire (or whatever) since it is a lot easier to damage the ensorcelled player with ranged or AoE attacks than with a greater restoration which is a touch spell. Nothing in the Vampire's Charm description indicates that it is different from the Charm spell; it does specifically refer to it as magic, rather than innate.
Is there something that I am missing?