Not sure why that happen, however the best way to screen a potential tenant is to see how they have performed in the past. 

Or are they performing some sort of arbitrage and they are not the end buyer.

Put together a spreadsheet and compare the performance of the subject property if you keep renting it as is for the next 10 or 20 years versus if you rehab and refinance.

He wasn’t performing for me, he was just giving me super helpful, targeted advice.

And, past performance is no guarantee of future results. 

If it is later found to be the work was not performed according to code or properly repaired, we will seek damages from your firm since you knowingly hid this from us and would not allow us to understand the extent of the damage which occurred behind walls.Thank youThis way you are putting them on notice that you were aware damage occurred and they did not allow you to properly inspect it.

That is if purchasing EXISTING performing investment real estate AND have very good clarity of every facet of the transaction ESPECIALLY reasoning for seller selling, AND you have decent market intelligence. 

He had performed virtually no underwriting.  

This is purely anecdotal, but I've noticed that the top performing properties in my area lead with an exterior shot.

@Leon G. whether or not you decide to go fsbo or use a realtor you'll need to use a QI to perform the 1031 exchange for you if you want to tax on the gain from your sale (and depreciation recapture).