Rocker arm troubles...

[971of1000]

I was on the highway in my 07 mini cooper s with 42k on the miles. It is completely stock. All of the sudden a rocker arm popped off cylinder 4 on one of the intake valves. I live in Joplin mo and was 150 miles away from the closest dealership so I had a person at a local dealer check it out before I towed it the 150 miles. He pulled the valve cover and the rocker arm was sitting in the cylinder head. So I brought it to mini this last weekend and it is out of warrenty by 8 months time wise. I have been on the phone with Mini usa and they have denied me assistance because someone other than a mini dealer looked at it. Call me crazy but I don't think rocker arms just pop off randomly? Does this sound like mini is seriously dropping the ball on a car (07) that has a history of motor issues?