i've always wondered why people were recording before these kind of things happened
It honestly doesn't happen much.
Compare the large amount of bomb explosions, car crashes, plane crashes and whatnot that happen everyday which are never caught on film, to the few that occasionally are.
It's only due to unusual circumstances (compared to the majority of the world) that any of these are sometimes caught on camera.
Take the meteor over Russia. The only reason there's such a large stock of footage of it is because of how many Russian drivers have cameras on their vehicles for insurance purposes. That's not a very common thing in other countries.
And I suppose this being Afghanistan, chances are that cameras are on to take footage of perhaps any suspicious activity or even in case of IED's or whatnot.
I'm fairly certain it's against cargo flight protocol to not have the cargo strapped down, would I be correct there?
Same here.
I don't know the full facts about what exactly caused the crash, but there are chances that the cargo was strapped down, but those straps faultered during the flight.
Eitherway there's certainly some fault here. But whether it is entirely down to a single-person or crew or not isn't truly known.