[Reffing Rev.]

B1 intercepts a pass at B3 yard line such that his momentum carries him into B's endzone. While in the end zone and trying to run out of the end zone B1 fumbles the ball. The loose ball in the end zone is either (A) in flight or (B) grounded when A1 muffs the fumble which bounces at the B1 yard line and then rebounds untouched into the end zone where B1 recovers with a knee on the ground.

What is your ruling in A and B? NFHS code, but feel free to discuss NCAA as well.