ArduCopter 4.1.3 - Debug pins + ESD issues

Hi. @tridge
In the release notes of ArduCopter 4.1.3, under Bug fixes, section C:

Debug pins disabled by default to prevent rare inflight reset due to electrostatic discharge"

Could you please explain what triggered this change in the code ?

Did you actually encounter cases of sudden resets with no apparent reason ? how would you tell if it was caused by ESD ? Any reported anomalies in the logfile ?

Sincerely, Guy.