What was the range of discrepancy?  

It shares a meter and furnace with the 1st floor apartment, but has its own vents.What do I make of the discrepancy between these various entities including the appraiser?

I told him of the discrepancy and forwarded him all the email exchanges that shows I have informed and the lender (loan originator) knew the property is duplex.

Obviously, the larger mortgage payment on the more expensive asset accounts for some of this, but I assume there is more to it based on the profit discrepancy. 

@Samuel FigueraWithout going into how you got into this predicament - that’s a large discrepancy.

Then I pointed out the discrepancies in the amount per units and the valuation he used on our property. 

If you are doing your due diligence and uncover discrepancies I'd walk if they don't drop.

There seems to be huge discrepancies between what various agents, friends, etc. tell me.

We did send them the PM an email letting them know we had the original invoices with a breakdown of the discrepancies and the balance they actually owe us to counter their claims that we still owe them money, which appears to be what resulted in the email from their lawyer. 

She’s got tons of great data points on the discrepancies between current cost of living ratios and those of our parents, but who doesn’t already know this?