Berkeley Multifamily - Discrepancy between County and City record

[Andrew Strauss]

Hello,
I am looking to buy a 3plex as an off-market deal from a friend of a friend in Berkeley.
The property is zoned as R2. The Berkeley rent board lists 3 units at the property. The Berkeley GIS website lists 3 addresses at the property. And there are 4 PG&E meters - 1 for each unit plus 1 for the common areas.

Alameda County assessor website lists the 'use code' for the property as 2600 which is "3 units, lesser quality than 2300 or unknown legal"
I had stopped by city hall right before the shutdown and after a quick initial search, they mentioned the property is listed as a duplex in their records. They said they might have to do more research and look for permit history to see if the property was ever approved for 3 units. And then the lockdown happened.

My question is - what is the source of truth? County records or city records (which seem to be incomplete or potentially missing docs)?
Have you guys seen a discrepancy like this in records?

I appreciate any help.