COMMENTProblems with equipment seem to be a relatively rare occurrence, but can happen to any diver. Good maintenance is the key to avoid surprises during a dive that could put the diver at risk.
Proper buoyancy control is a fundamental skill to ensure dive safety. Effective training would have ensured that well assimilated safety procedures were followed - like pushing the deflator button to avoid an uncontrolled rapid ascent. A rapid ascent could be a life threatening incident, triggering anything from decompression sickness to a lung over expansion injury and even an arterial gas embolism.
~ Sergio Viegas