They were a bit older than me and a smooth talker, and he knew everything about contracting... allegedly. .

Here is one example, admittedly not the best, but its on the MLS now, so let's use it for discussion purposes. 

Show the lease agreement, show his rent payment history, and show any written evidence from the tenant that he admits to being late/unpaid.

I admittedly have a bias against condos for the following reasons:1) HOAs - both a lack of control over fees and assessments, as well as potential regulation changes2) they don’t appreciate as much3) you have to work a lot harder to differentiate yourself from your neighbors. 

It sucks to admit that there wasn't tight oversite on the deal to ferret this out b4 the sale happened and its subsequent consequences and it sucks for your client that they have made, for at least the time being, an investment that is not going to be in the black in the immediate future. 

I would recommend getting the tenant to admit that they had done something to cause the problem.

I admit I have a lot of regrets with this one but I’m learning from my mistakes.

The only policy I could find that would cover the building is a surplus-line, non-admitted carrier in CT.  

Santarelli allegedly purchased from a government auction from the bankruptcy trustee and relaunched online.

She wont admit anything and neither are her guests.