Nah. The problem does not repeat, sorry.
Also, I suffered a lockout just this afternoon, as follows: I shut the player off (was playing via Rockbox before shutting down), I had shutdown the normal way, via power button.
I drove home with it in a belt pouch. Later, I took it out of the pouch, this was 3 hours after shutting it down, hooked it up via its USB cable to my laptop where it has always worked. Sansa wasn't recognized by the laptop, and nothing happened on its screen. I could not get it to turn on. I locked the lock button, pressed record button and pressed power, then the player started up and complained about being locked, then shut itself off. I pressed power, it started right up, and the battery indicator showed more than zero, but close to empty.
Possibly the device got powered on while it was in my belt pouch, but the battery graph seemed to show more than empty when it finally started up.