Zoning question (zone map vs. appraisal district)

[Jose Matuk]

Hi everyone, I'm currently evaluating purchasing a duplex, and when I searched the zoning in the city zoning map, it says it's in a R-5(A) zone. However, in the appraisal district the zoning section says multifamily district 2 - with a city code MFR-Duplexes.

I already tried calling the city planning and they told me to send an email, which I did but haven't heard back. 

In this case, what source is more reliable (considering that the maps have a disclaimer that it could be inaccurate)? 

Last thing I want is to get a duplex only to realize it's only legal to have a SFH in there. Thanks!