Yes, marlin will jump like a kangaroo when startled like that.
And I'm almost certain you are right in observing that the camera man was already in the water. I don't think jellyfish or sea turtles run around making videos to send to Americas Funniest Videos like humans do!
NOW, if you want to see some true grit, go to youtube.com and type in "noodling".
There are a LOT of inebriated redneck types (ie, everyone I call family and friend!) that willingly wade around in muddy water just for the chance to stick their entire right arm into the mouth of an 80-pound catfish!
I've always wanted to do it, but I lack the tolerance for the amount of beer required, and the fact that my wife will KILL ME if she finds out what made all them cuts on my arm!