Timing and crankshaft pulley

In the process of doing a timing belt and water pump replacement. Had the timing marks aligned and when I was trying to get the large center nut off of the crankshaft pulley and the crankshaft pulley somehow turned about a 1/4 of a full turn while the top two pulley's did not turn because I had them locked into place. How and why did this happen? Could it just be that the pulley just turned and not the shaft? Do you think it could have bent or broken some valves? What should I do? Can I do anything? Also, not sure if it is relevant but I had the TTV solenoid off the top of the cam cover.