“Now the FB is left holding the bag and is only taking what legally belongs to them”
I have a few problems with this. First, you state several times that the FB is THE VICTIM. I disagree with this. Then you make the assumption that the FB legally OWNS all the ‘upgrades’ that they are taking back. If they can’t make the mortgage payment, what makes you think that did any of this remodeling with their own cash? It was likely borrowed money that they got via a HELOC, cash back at escrow or a refinance.
Edit: looks like the last sale on this house was in 2001 for $325k (per zillow). I’m now strongly convinced that our FB here did a couple of withdrawals from the house ATM and is now upside down in the house and decided to just walk.
I’m even more convinced now than I was before that these people are a couple of tools.