Can a town be wrong about how they assess a home as a three unit?

[Nancy Chin]

Can an assessment be wrong? A neighboring multi family recently changed hands and the town assesses it as a three family but the old landlord was in violation not too long before she sold it. She was renting her attic as if it was a legal unit but it wasn’t and she was forced to remove the third tenant. 
If they rezoned shouldn’t they have gotten approval at a hearing from the rest of the neighbors first? There are too many cars now on our dead end street and people can’t park in front of their own houses due to the over crowding from this unit. It’s become a hardship, very stressful. The owner of this unit has a big long driveway for four cars but parks in front of it and none of the other tenants ever use it.