Videos like this one make me instantly call BS every time a shark "expert" explains that shark attacks are 99% of the time test bites, and that the animal realizes it's mistake and swims off. I do understand the strategy of staving off animosity to sharks so that the general public doesn't cheer on Chinese fin harvesting, but lets be honest, sometimes sharks mean it.
No mistaken identity in the case being discussed or with the fatal incident in Sydney, Australia last year and no doubt many others. The view taken by most recreational divers on the subject is naive, bordering on a Disney-like perspective of the world. Great whites, tigers, bulls sharks and one or two other species are big, dangerous predators. Fortunately, we swimming monkeys aren't their normal food source and they generally leave us alone, but if the opportunity arises and conditions are right...