A few weeks ago I had a wicked crash of my quadcopter (APM 2.0 with sonar). It suddenly took off in one direction (without waypoints or input from me) but eventually came back to its hover point. I started a fast decent, but when I gave it more stick to slow it down the throttle seemed to give out and it slammed into the ground. I was only in the air for 5 min, so it wasn't just a dead battery.
After replacing the broken landing gear, I went to download the log file to see where things went awry, but there doesn't seem to be any record of a flight on that date. I've got 40 or so logs from earlier dates. There also seem to be new logs from today, probably from powering up the APM via the USB to download.
How is it possible that there was no log recorded from that flight? I had good power and GPS lock before taking off. Does APM have the ability to suppress bad memories? Is there somewhere deep in its subconscious that I should be looking for this log file?