The lockout is at the domain level, not the VM level. So that makes no sense that restoring a VM from a snapshot would allow this. Maybe if you restored your DC to a previous snapshot that had your AD data in it - but other than that restoring a VM (not DC) would not fix this issue.
Sounds to me more like the VM was removed from the domain at some point after the snap was taken, so you reverting back to the original snap restored to the spot before the removal of the domain.