All I can offer from that picture is that they somehow lost control (possibly a practice failure on the runway during take-off), maybe close to lift off speed, pushed forward to somehow make it stick to the ground (bad idea), left the hard stuff and the nose wheel has dug in causing the aircraft to flip. Only problem I have with that is the lack of mud on the nosewheel and whether it would be able to take the load of that sequence without breaking off...