After the lender did a soft pull on their credit just before closing they then denied the loan.

If they feel like they got screwed, we have choices: 1) Deny what they feel, and rationalize what we did; 2) Accept what they feel as their biased perspective, and feel comfortable with what we did; 3) Accept what they feel as having some validity, and look for ways to improve our work in the future; and a number of other possibilities. 

I have been denied claims many times when something doesn't meet the definition of "suddenly and without warning".  

Guess what happens if you get a homeowners policy and there's a fire on a vacant property in the middle of rehab ... claim could be denied. 

I did speak with the seller to request an extension but she kindly denied.

He is telling me I would initially get denied and then we would file for an article 78 and most likely win. 

Some insurance companies will deny you coverage for certain dogs.

Mike Hurney I did make the $710 offer but unfortunately it was denied.

First, @Cal C. is right, using the term flip to even describe your activity and stating from the outset that your intent is to resell at a specific point in time automatically opens the door for a field agent in an audit to determine that your intent was resell and any 1031 denied and ordinary income rate applied.  

Which is not to say that they will outright deny you, but don't forget there's a subjective human aspect of underwriting.