The other hard part today with proving/disproving things like this is there are so many people out there with the ability (and for some reason the desire) to create fake images/videos that are done just to mess with the general public.
The idea of educational documentaries has faded away in favor of ratings. Mockumentaries have become the trend. You get the very obvious fakes like Finding Bigfoot and the mermaid show.... ok, clearly 98% of the population knows if we discover either, it will be on ABC's nightly news, not a TV series. But when you start to cloud the public with things like fake documentaries about megalodons on Shark Week or even films like Blackfish that are agenda driven and misleading, it becomes hard for the public to draw the line between fact and fiction.
As an example:
A few weeks ago there was an article circulating the social media sites with an attention grabbing headline about something eating White sharks. When you read it, it makes you think there is some gigantic creature taking out the apex predators. In reality, a tag on a 9 ft white gave some readings. They included a temp change (increase) and a pressure change (increase). Right off the bat, we all know a 9 foot White shark is fairly small - and didn't match the image of the 20 foot shark pictured in the article. They say the temp increase was showing the tag being digested by a large animal. Maybe, or maybe it was in warmer water. They say the rapid pressure increase showed the shark was pulled quickly to the bottom by it's attacker. They forgot to tell you the same reading can happen with a large animal bites a tag (rapid pressure increase) and damages it. They also lead you to believe the shark itself was going through the changes. In reality, all they know is the tag was reading it. The public doesn't know how often tags are ripped off and send bad data. They don't think about something grabbing the fin the tag was on and swimming away with it. The writer went for the most dramatic attention grabbing version - which ironically is also the least likely to have happen.