If this attorney/developer is so sure it exist why has he not provided you with a copy? If he couldn't find where is was canceled that means he "searched" so once again I ask why hasn't he provided this document? Also why have you not demanded the document instead of flapping gums? It is obvious you want/need it to be true. With a copy of the easement even I with my limited knowledge of doing title searches and an afternoon in the records room in Dadeville I could search it out for you.
I will say this again, if any deed is recorded without a previously properly recorded easement attached to it there is a cause of action against whoever wrote the title insurance,even though it is not an adverse easement in this case, easements attached to deeds are part of the deed and must be recorded with all subsequent deeds. Someone needs to put up or shut up. You claim to have visited with at least two lawyers on the subject yet neither has offered any more proof of this claim than I have. The alleged Court case would be public record and easily searchable by any lawyer. Free legal advice is worth less than what you pay for it, which is nothing. Hire a competent title abstracter and you can have your answer in days, if not hours.