This sounds exactly like what the Australian Navy had with their fleet of AS350's in the mid to late 80's, with cracking and debonding in the canopy. They decided it was due to the twisting stress as a result of having the aircraft tied down to the ship's deck while the ship pitched and rolled. Not saying this is what caused your problems but just pointing out that it has happened before. It took months of repair work before the problems were sorted out. Eurocopter should have plenty of knowledge of this problem.