Good attitude and post, Frank. I think at this point, I take exception to the fact that Scuba Sciences refuses to acknowledge even the possibility of what you state: "We are all human and I know that I have blundered and made mistakes in my professional and personal life."
They don't have to take responsibility, but they shouldn't foreclose any and all possibility that it was their mistake, and they should at least assure the customer that they'll be doublechecking this in the future. Their attitude is more like, "You can't prove we did it, and we're not changing our behavior one bit. You can either accept this by letting us continue to service your equipment, or you can take a hike." After a dangerous and scary OOA accident, I'd hope for a bit more, too.