2004 Chrysler Pacifica Doing Timing Belt Water Pump Tensioner Pulley Change

I am doing a timing belt, water pump, and tensioner pulley change. My question is about the camshaft, my buddy was trying to get the timing marks lined up but instead of rotating the crankshaft, he turned the right camshaft and he turned it full revolutions a couple of times, i heard this causes engine damage, what are the chances he has ruined my engine by doing this? thank you and god bless