I always recommend the seller offer full disclosure. If a buyer or buyer's agent feels you're hiding something, it's unlikely they'll want to deal with you.
Keller Williams Realty - Atlantic Shore
Generally, when taking a listing, we give the seller a multi-page sellers disclosure form. That is the place to disclose any, and everything you know about the home. If anything isn't working right, the best thing is to state it then, on that form.
If you have knowledge, due to a cancelled previous contract, of a problem, you should absolutely disclose it right from the start. It's too late to disclose after a contract has been signed, and you are in the attorney review period or during the inspection
Now............in regard to the issue you say was proven false by 3 experts...........that is your call.........however, .since I don't know what the specific issue was........if this is something that is still open to interpretation, I would still state it, and show the proof you have that the issue is a "non-issue".
The best advice I can give is...................When in doubt........disclose!!
Hope this helps
Prudential NJ Properties