It was a tailstrike of very minor contact...
I observed the tailstrike incident and at the time I though the skid may have missed contact by millimetres as there was not sparks, smoke, dust etc coming off the skid.
It appeared to be just a slight over-rotation - as the takeoff appeared normal until the aircraft commence the initial lift-off after the standard rotation and rise of the front wheels.
However the aircraft did not lift-off the runway as per normal a second or so later, hence the pitch increased until just as the tailskid appeared to possibly just touch the runway the aircraft lifted off.
The thought crossed my mind as to whether the weights and measurements were correctly added to the FMS or if someone did not correctly list all the cargo...
Either way it was a very minor tailstrike and SOP's would have no doubt dictated the aircraft return for a safety check.
River