I haven't seen anything on this subject, but this can be a great resource for providers to use in checking outcalls. Go to this link, the Harris County Appraisal District. This link
http://www.hcad.org/records/real/default.asp and search on name or address for outcall. If it matches up you have additional insight to the person your meeting. This will not work for renter but if he's a homeowner, I would think your get to go.