Unable to move or open menu after I probably should have been dead

I was fighting a guy with a rapier on the bridge near the firepit in the top-left corner of Mariner’s Keep. I was low on health and took one hit, then killed him. While moving on I noticed my healthbar was empty and stopped walking. Afterwards I could not move anymore. Opening the menu was also not possible. I guess there was something up with my remaining health. I had to quit the game with Alt+F4. After restarting I could continue right from where I left off with full health again. Unfortunately I don’t have a video. Here are the requested files: WeTransfer - Send Large Files & Share Photos Online - Up to 2GB Free