R1 on 2nd with 1 out and B1 hits a deep shot to CF. F8 starts to track the ball toward the fence on a full sprint and catches the ball but his momentum takes him another 8 strides into the fence and violently crashes, the ball comes out. Is this a catch?

A fielder who catches a ball and then runs into a wall or another player and then drops it has NOT MADE A CATCH. When a fielder by his actions of STOPPING, Removing the ball from his glove, etc signifies the initial action  is completed will be judged a CATCH.