I know it doesn't answer your question, but think it's a good idea for your consideration.
Wow, what a deal. I agree with Ute. Talk to the seller's agent. Ask her to inquire for you. Talk to the Agents broker as well. Be sure to ask for some monetary assistance to the buyers. Don't be specific about where it will come from. Let them figure it out. It is very unfortunante. We see this stuff happen all the time. You wouldn'tthink you would have to move all of the furniture to check the condition of the carpet.
We found that there are now actual court cases - setting precedent, whereby the sellers in one particular case were sued (our state has a 2-4 year time-line to sue), and the buyers got ALL their money back including all court costs, loss of monies tied up in the sale/purchase AND the sellers had to take the property back!
MY PONT - FIND OUT your local disclosure law, call your real estate hotline (outlined on our PA purchase contracts) and get the 'scoop' of what recourse you have.
Also check whether your buyers signed off on the walk-thru - even if they did they may STILL have recourse!...Hope that helps...
Removing built-ins is another issue. If the trim is incomplete after removal of what was there when your clients made the offer, I would say they removed fixtures. The question is whether it's worth fighting over it. Your clients would have to take the sellers to small claims court or arbitrate/mediate the issue if they agreed to alternative dispute resolution in the contract and I don't know if it's worth the trouble.
As far as the storm doors are concerned. I'd just forget about them as they were not in place at the time of the offer and unless they were specifically mentioned in the contract as included items, I don't think they were included in the purchase. If this happened to me I'd talk to my broker and see what I can do to help my clients. Sometimes you have to open your wallet even after escrow to make the client happy. I'd probably make some monetary contribution myself if neither the seller's agent nor the sellers do the right thing. Sorry you have to deal with this unfortunate situation.