Why don't you call the one source who has the absolute answer. Call HAL. And if they say it is okay, get them to e-mail or fax that to you in writing. I seriously doubt they will permit it but it is possible that if you agree to pay to Passenger Carriage Act Violation Penalty....maybe they'll allow it?? Can't hurt to ask.
Also.....remember they have your credit card number so don't think you can 'pull a fasty'.