There is a "down" arrow on the left side of the comment text box, the purpose of which is to discard the comment draft. When tapped on it, a confirmation message appears.
But if the user taps on the hardware/on-screen Back button and the app traverses to the previous screen, a drafted comment is discarded without showing any confirmation message.
I'm using version 1.0.43.
PS: I'm experiencing a lot of force closes lately.