When did they change the balk rule?

[GoodwillRef]

I am working a college conference tournament this past weekend in Green Bay, WI, and in middle of the 9th inning (storm clouds rolling in) get really dark and my first base umpire comes in and asked if I can have the lights turned on he is having a hard time seeing, usually do this at the start of an inning but we have to be able to see the ball. I have the home team (down by 3 runs at this time) turn the lights on. The visiting coach goes crazy yelling at me, "In the middle of an inning?" I replied "Coach I asked them to turn them on...you also want to be able to see fly balls and pop ups...don't you?" They calm down a bit. Bottom of 9th...first batter grounds out...new pitcher and new third baseman. First pitch the batter hits a foul popup behind third about a mile high and the SS runs about 25 yards to make the catch...maybe he doesn't see it without the lights on. Next batter hit another pop up on the infield a mile high and the SS catches it and they win the conference tournament. Coaches will argue just about anything!