What really irritated me about the Viva Amiga project was that the guy was doing special showings, showing up at computer shows, talking all about what a great thing it was and most of the backers still hadn't even been able to see it.
This has happened to a couple of other kickstarter documentary projects; what happens is that the filmmakers either run out of money, or want to make a profit, so they shop the film around for distribution. If the filmmakers are upfront about this at the very beginning of the kickstarter, then the backers can make an informed decision. When they
aren't upfront about this, you get pissed-off backers.
I backed the (excellent!) James Randi documentary and received my digital download almost two years after the film was finished -- I had
pirated it off of a BBC channel well before I got my official digital download, which greatly irritated me. The backers were literally the very last people to see the film they had backed. The filmmaker's response was that the digital downloads were DRM-free and they didn't want the movie to be pirated before they had a chance to make a distribution deal, but honestly that's a lame excuse given that they licensed it to a public BBC channel nearly a year before.
In the case of Viva Amiga, I've been told (I'm not sure this is true, please verify independently) that the filmmaker didn't correctly estimate the amount of money needed to finish the project and ran out, so the distribution deals were to get additional money to fund completion and creating the backer-unique items.