UI disappears when fullscreen video completes

[dmnd]

1. Lock screen in landscape mode
2. Start a video
3. Make it fullscreen
4. Wait until the video finishes
5. Observe black screen with no UI.
6. Tap the screen
7. iPad, wifi, time, battery status appear at top of screen, but everything else is black.
8. Tap screen again. Screen goes blank.

Rotating the screen seems to bring it out of this weird state and the blue "Done" button appears so you can get back to the app.

[dmnd]

After tapping "Done", the UI reappears with a blank video witha play button. There is a loading throbber that looks like it's never going to disappear - I don't think anything is actually being loaded. This is on an iPad 1.