Ouch, that's a big problem- thanks for sharing the vid! Last question, are you on the latest version, 1.7.0?
I was playing around with this a bit with a friend and we found that sometimes when you hold a piece right as it's locking into place that can cause you to get a floating piece in the middle of a field. We think this might be related since similar conditions seem to trigger the game over - maybe the game over is a floating piece that spawns at the top of the screen? I'll try to share some recordings when we can get some.