On a semantic point - Pegasus and Mainair were historically different companies, which merged a few years ago into P&M Aviation. Both brands were continued, but the Pegasus brand has carried on more strongly longer, and the type is a "Pegasus Quik". Gorgeous aeroplane to fly the Quik, but does require a fair bit of precision in your flying compared to the previous generation of flexwings.
Looks like a classic "rollover" accident, which used to be regularly fatal until it was realised that the major crashworthiness issue was restraint of the rear seat occupant (their bodies were coming forward and on occasion breaking the neck of the front seat occupant). Mandating rear seat upper torso restraints about a decade ago fixed that virtually overnight.
So whilst very happy to hear it, I'm not particularly surprised that both occupants got away with only minor injuries. The speed this all happened was probably around 30mph. I'm guessing strong and gusty winds, probably with a significant crosswind component, which would be consistent with the type of accident.
A very nice aeroplane has been destroyed, but that's what insurance is for and they can build another one.
I'm sure that AAIB will do their usual competent job - but with two PoB to interview (and photographs!), their task is happily relatively straightforward.