“In a pretend hug, he disconnected something on her breathing apparatus and allowed her to sink to the bottom. Did nothing to help her despite his expertise as a diving expert.”
Its actually quite easy to turn someones air off without them knowing. When I went through the training my instructor did it several times to practice out of air situations. She should have went for the surface but he probably had her over weighted.
Oh, and as far as being overweighted just about EVERY novice diver overweight themselves.