Not part of this, but I have experienced in the past sporadic download corruptions with users. I've never figured out the exact cause, but a reinstall has always solved it. It's been roughly 10-15 users out of 25000 or so purchases. My best guess is that some part of the distribution pipeline does not fully validate the app package and re-download it if it fails.
It seemed to effect US users around noon PDT, and then a batch of international users around 5 pm PDT.