Fake buttons definitely can initiate the download of an executable file pretending it's a movie; there's nothing unusual (tech-wise) with it. Once in while, I do experience them.

There are countermeasures in place by some browsers/versions (that is, blocking of downloads with executable extensions), but non-savvy users can be tricked - the concept of file extension/type is not so clear to them, and it also assumes that the user is giving the right attention.