Yeah that was a bit of an "oops". There was indeed water on the floor. Turns out last night I must have bumped the RO/DI line because it was just dripping onto the floor and the sump water level was still way down.
DUH! Oh well, with the tapwater being so cold right now the RO/DI's production is WAY down and there was surprisingly not as much of a puddle as one might have thought there would be for 12 hours of RO/DI dripping onto the floor.
So naturally instead of turning it off, I just put the tube back into the sump and left for work again (after I wetvac'd the floor some). In the meantime I have a really nice clean spot on the floor in the closet next to the tank room. The one silver lining is that now I know where I need to shore up the silicone along the floor to help contain floods. The front edge of the tank is completely dry so the silicone there either did the trick (or the water didn't run that way).