We are sorry about this unfortunate experience. Providing accurate information on a sinerio such as yours is most difficult because of the lack of information. We are certain there is more to this that a real estate attorney would be able to reflect on with complete and accurate information.
Our recommendation is if you feel you were takeen advantage of seek an attorney for their review of the situation and possible recommendations.
The Seller Disclosure is very specific. 3a asks the date the roof was installed; 3b asks directly if it was replaced or repaired during their ownership. If they checked "No" to this on the disclosure, and you can prove they repaired it in '03, you would have a strong case.
The trouble would be proving it! Since the roof is leaking again, it obviously wasn't repaired very well. Does the neighbor remember if they hired someone? Usually roofers and other contractors put a sign in the lawn while they're working. Perhaps she remembers who did the work.
It is also possible they did the work themselves (explaining the shoddy workmanship). If they did the repairs themselves, and deny it, perhaps you can get a roofer to inspect it now and testify as to what he thinks happened. (Sound like you need a roofer anyway.)
Be sure to take lots of pictures of the roof before you fix anything, and keep good records. Write down what the neighbor said. Ask if the neighbor is willing to testify in court, since that's what might eventually need to happen.
You might also run a CLUE report to see if they made any claims on their homeowner's insurance. If your insurance rates aren't high, perhaps they never reported it. Good luck!
(And *always* do a home inspection!)
I recommend getting a CLUE report on the house from your insurance agent. A CLUE report will tell you if any insurance claims have been filed on the house. Perhaps that may lead to a paper trail of the roof colapse. If it was repaired by a contractor then maybe there is some liability there. Unless you can find a paper trail to prove the roof collapsed, you will have to rely on eye witness reports. My guess is that since there is $25,000 worth of damages then the homeowner patched it themselves and there is no paperwork. It sounds like you have a good case, but can you prove it. I am not a lawyer nor do I play one on TV.
GreensHome Design L.L.C.
Home Design & Home Inspections