Another spontaneous reboot earlier today. It actually rebooted twice so the logs from just before were rotated out of existence, but in both the ones I had left the boot reason was 32wd_to this time.

I don't know if it's significant, but at the time I was logged in via ssh and running BMEFree.py (testing power drain when using a particular AP). The tablet was otherwise idle and the screen off and locked. The battery level was ~90%.