I call ********. My divebuddy (who has 13 more dives than me, but who's counting?) was well prepared (and positioned) to experience my moment of panic as I breasted my first wall. She laughing blew almost as many bubbles as me in panic mode.
We both still enjoy natural shark encounters.... Saw a few on every dive on our last T&C trip.
I think there is a big difference between those that are afraid of (fill in the blank), and those that are prone to panic in their phobia environment. My wife has a fear of spiders, but when confronted by one, she will pick up a shoe and smack the crap out of it. I do not have a clue how to advise people that are prone to a panic response. Fortunately most people do not fall into that category, and can overcome their phobia by slow, patient, and extended exposure. But no one is going to be able to talk a fearful person out of their phobia by quoting statistics.