This actually happened to the recent club cricket game that I played last week. We needed 6 runs off 11 balls and had 3 wickets in hand. One of the batsman played a shot and ball was rolling slowly towards the boundary line, all of a sudden a kid (age ~7) took about 10 steps into the ground and tried to grab the ball but it went over him hit something and jumped not reaching the boundary line. Since kid made the interference batsman and umpire lost sight of the ball and they (batsmen) did not finish the third run wondering if the ball was caught by the kid or went to the boundary line. Meanwhile, fielder chasing the ball continued running and pick up the ball, threw it back to the keeper and they made an appeal for the run-out.
Now, fielding side wanted the run out and batting side wanted the penalty 5 runs or to keep 2 runs which occurred before the interference or even redo the ball/delivery.
Umpire decided to play "fair" so he split the points (5 each) and called it "everyone won". Fielding side took this decision promptly and happily and quickly started packing while the batting side wasn't happy with the decision.
Now I wanna know, did the umpire made the right call? What are the rules/law for such cases?