Big Crash possibly due to brown out

Dear sirs,
Hope someone can take a look at the log file and suggest what I should look into. I went thru the logs per the ardupilot wiki but still would be happy for another per of eyes.

I’ve been playing with the copter a bit and towards end of the battery wanted to do some “jumps”, after bringing it to stabilize I gave full throttle up and after few sec. it tilted and crashed hard on concrete surface…
The auto log analysis suggests possible brown out… hmmm.
I have 3dr power module (clone) powering Pixhawk Lite + backup 5V supplied by hobbywing UBEC into the servo rail. No capacitors or diode on the servo rail.
I’ll be rebuilding in two weeks and very concerned with this occurrence.

Log - https://www.dropbox.com/s/x7ayu567menn5iw/14.BIN?dl=0

Thanks, Eddi