Saw it happen, appeared to lose power on take off, leaving her slow and at the back of the drag curve with the enivitable stall / spin / ground loop. Hit the grassy ground to the north (RHS looking down the runway).
I believe they were taken to the local hospital for checks. Thankfully the word from the tower was all on board are OK.
On Flyer forum is was said that G-APRR was involved.