The records were sealed to protect the location of a sunken ship: "....and other confidential information with respect to a sunken vessel contained in the exhibits."
The reasoning for the suit could be anything. Maybe it's all bogus. Maybe Dr Lyons leaked some info he shouldn't have. Maybe Dr Lyons was being paid for researching their sunken ship, and while in so doing, he may have also been on somebody else's payroll doing research along the same lines. Maybe maybe maybe maybe maybe. WHO KNOWS?!? Although, I would like to know the answer. It may answer a question about the man relating to a completely different subject.
UPDATE:
After reading through all the available documents, it looks like Blue Hole Expeditions sued Dr. Lyons and Northern Oceanic Research & Tecnology(sic) Holdings, LLC (NORTH - LLC). After entering into an agreement between North-LLC and BHE, "North-LLC" demanded an additional $2 million for their ship to leave the dock. It never left. Now, a third party is in the running for the same sunken ship. Looks like Lyons and his trusts are being sued because of possible income loss to the third party.
I detect the history: I've visited archives up & down the entire US East Coast, Bahamas, Jamaica, Kew, The Hague, etc. Have yet to go to Seville or S.American archives.