That dude stayed really cool, and handled that well. It was lucky for him that the shark went for the fish before he had the fish to hand.
Like a lot of kayak anglers, I use a "lip-gripper" for bottom fish, rather than a net. I like a net when I'm fishing for salmon or trout.
I was in the Marine Corps at the time and had been 200 miles inland in the outback basically for wargames for the previous two weeks. They trucked us to the coast for a couple of days of R&R and I was just happy to not be sleeping with scorpions and spiders and didn't think about the nasty things in the water at the time.
On a trip to Oz back in the 90s my buddy and I dove and snorkeled on the Great Barrier Reef out of Cairns on the east side.
All we saw were small blacktip reef sharks.
Although I've seen some pretty large six-gills here in Puget Sound (not diving, just due to knowing some aquarium marine collectors) those little tropical guys were enough for me! Wouldn't want to meet up with their larger cousins!!