Note investing and tapes of notes

[Donald D Michna]

I recently was able to get in contact with someone with a tape of NPL . During my due diligence (searching each county GIS) I found that some of the properties have different property owners than what is listed on the tape. For me this is a big red flag. Is this wrong for me to think this way? My understanding is that before a property is sold that the note would have to be resolved. Just a thought, but is this a bad tape? Is this individual trying to sell old paper? On the other hand is this tape so new that nobody has looked at these notes in years? This may be the case, as in a particular city many of the notes were foreclosed on by the city. What are your thoughts?