Sounds like the AAIB need to be on standby for this character!
Im interested in the comment about leaving the engine running with the blades not turning?? I am presuming that the clutch was dis-engaged but the engine was running?? Even so...there is still friction with the Drive belts and the sheaves on the drive shaft. I wonder how long it will be until the belts fail in flight with some poor unsuspecting Self Fly hirer in command who has to perform an emergency landing (Hopefully) due to the actions of someone who used the aircraft hours or weeks before! Maybe it would be better to name and shame so that the aircraft can be grounded and checked before the next flight????
This is coming from my experience of being involved in a serious accident a few years ago caused by a ticking time bomb in the aircraft caused by another weeks before.
Flash