thing is a lomcovak is a negative g manoeuvre, blood goes to the head so greying/blacking out doesn't happen.
and compared with what else you can do in such a plane is not very high G either.
of course he could have had a physical problem or something jammed in the elevator/rudder - all speculation really and we should wait for the report.
Its all very sad for all his friends and family and a reminder to all who do aerobatics that at display/competition heights a parachute is often of little use then things go wrong