Windows 7 Home Premium 64-bit and Java 64-bit
When you pause the game and wait a little while the game will continue but time will speed forward and continue. The reason why I think this is a bug/glitch is that when continued, you have a chance of getting killed by mobs and other things. My incident was when I continued I was in my new shelter and was shot by a skeleton many times and died in about a second.
Steps to recreate a similar event:
1. Start a new world with snapshot 13w41a
2. Pause the game for about 10 minutes out in the open so you are exposed to mobs.
3. Un-pause the game and wait to see if same incident occurs.