But numbers don't lie. 

Was the appraiser lying?

I have met countless charming people in the USA who were so bent they couldn't even lie straight in bed.Going and meeting them and looking at their houses is not due diligence.

If you don't tell him all the reasons you got a screaming deal, then he must assume it was an arms length open market transaction, which in turn will mean the other home appraises low, which may mean it sells for less, which in turn means one of YOUR comps sold for less, which could impact market value of your home should you go to sell or refinance it.I would be selective about what I would share, and I wouldn't lie, but I'd only share information that will, or could, lead to my property selling or appraising for more. 

They lied on their disclosure.

Non-smoker - they'll lie through their teeth on this one.

He has already lied to you before about the 8th so he has shown you that he can’t be trusted.

If he lied about anything else then reject him. 

I agree with @Jerry W. in that the greatest risk lies with you.

Percentages lie to you.Now, as far as the cost of the loans are concerned:1 - They both have upfront fees that are paid once.2 - The cost of use for a HELOC is applied every time you use it.