I had a very similar situation this weekend. Nobody on, no outs. Ground ball to third baseman, throws high and wide of first base. First baseman moves 3-6 feet down the line towards home, and leaps to make the catch, but cannot reach the ball. Runner attempts to avoid contact but clips the legs of the first baseman. Two tangled bodies fall to the ground. Fielder gets up to retrieve the ball, but the runner is literally on his back. The runner is carried about 10 feet toward foul territory. They untangle, runner touches first and is thrown out at second trying to stretch the hit to an infield double. I had nothing on the play, and didn't get any flak from anybody.