Scary!! Mister, don't do that to your mama!! I'm so glad to hear that he's okay. I would have been petrified too, and you betcha I'd have been right over at the e-vet!
Reverse sneezing is NOT THE SAME as collapsed trachea by the way. It's a pharyngeal reflex! Reverse sneezing is not dangerous(despite how scary it can look) and some dogs actually learn to do it for attention.