But unlike Orlando (based on 4 years of evidence) people actually will not have planned their Vegas vacations yet for 2017 so most homes will show low bookings right now. 

If his account was indeed frozen, he should have no problem providing evidence that this is indeed the case.  

If you are not...then you should be as the reason is evident.

I usually take photo's of my jobs as they are being done from start to finish to show behind the walls of the plumbing, electrical and studwork to have evidence of quality. 

If a faucet was replaced that would cost for parts and would leave evidence that work was actually completed.You should be informed each time what property the work was done in and call the tenant to confirm.

Now I find that the mortgage underwriter has stopped dealing with BlackRock, and he won't return my money because it has been spent (although there is no evidence of what it was spent on).

By requiring the tenant to provide me with the bill early, I have time to review, investigate if there is negligent misuse from downstairs tenant, and/or adjust of warranted (basically set rent reduction for upstairs and rent increase for downstairs for given month).Though, in 95% of cases no action is necessary and the upstairs would simply be responsible for the bill as there is no evidence of misuse downstairs, along with full rent due.All in all, as noted above, the increase is most likely due to natural increases due to hot summer months usage.  

I'd say this type of diligence on the part of foreclosed borrowers is more evident in higher priced areas and with properties producing income for the owners/borrowers (such as active farm and ranch operations, and of course mj growers).  

There is a lot of nepotism in banking and in mortgage businesses as well, certainly a good ole boy aspect.The other issue is that regulators and lawmakers are only aware of square holes, the secondary market, prudent lending practices based on statistical evidence of large populations.

Assuming the seller hardship, imminent default in this case, is valid...whoever is negotiating this needs to escalate with Freddie, with more evidence of the seller's real hardship.