Default [Q] Unexpected Flash Reset

I have the following: Galaxy S3 i9300 using OmniROM 4.4 getting nightly builds.

I was carrying my phone in my pocket and notice when I pulled it out that It was asking me to set up my account...Google, Google Now, What country I was in? It had reset on it owns but when I checked the storage, it still shows all the space is used but I can not access any previous data through file manager or usb connection.

I tried to flash the latest nightly to see if it would reset but it failed. Not sure short of wiping everything I can do?

Can anyone give some advice to get access to the data? there are some things I want....

Has anyone come across this happening? Did the device overheat or what caused this?

my battery was extremely low at the time when I looked at it.