Property noted as 4 unit, but 5 different apartment units?

[Adam Juodis]

I am looking at a 4-plex, and got some additional information that wasn't on the MLS from the selling agent today. It's a 3BR and (3)2BR 4-plex. The current owners split the 3BR unit into a 2BR and 1BR with separate tenants. Is this even legal? If so, does this have grounds to be classified as a commercial multifamily(5+ units) which could increase my taxes and other payments?