Ok, that is pretty much what I figured and what I do. I immediately go to backup and then sort it out. My biggest issue is that i really can't 'feel' a hose very well against my suit due to the level of gloves and exposure protection we wear here.
Another question for you folks: when do you clip off your primary to your chest d-ring? Is it just for storage and when you are breathing a stage?
You can find the hose behind your neck (its one of the 2 back there, the other one is your backup in your mouth)
Yes when you are breathing a stage the long hose is clipped off. Its also clipped off getting in and out of the water - assuming it doesn't need to be in your mouth for a boat entry etc.