rzr 1000 flip

I bought my first rzr 2 months ago, a 2015 rzr 1000 fox edition. previous to this many 4 wheelers. I am new to rzrs but not really new to off road. there is an 1/8 mile drag strip where we ride. this past weekend my son was racing and at the end of the strip locked the brakes up the thing slid for awhile with a pile of dirt building up in front of the front wheels and then it flipped over end over end the first time and then two more times sideways. I never would have thought this thing could flip like that on level ground and not jumping. has this happened top anybody else?