first of all when jumping it is good to hold the bars with both hands, secondly it is strongly advised to direct the body and bike into riding/jumping direction... being so high up above the ground is dangerous too. Unless he has just found out that someone had peed on his grips, that behaviour is very disturbing
Nothing to do with Nikon, using the old school Pocket Wizard Multimax's with the trick I figured out... I can do it way more easily now with the Pocket Wizard MiniTT1 or FlexTT5's, but I can't sync quite as high, probably only 1/1250th or so...