Terrible Person?

I was reading an article on The Royal Tenenbaums and talked about how the cast bonded over there hatred of Hackman. How he was an absolute ass to everyone on set and when everyone got together all they did was talk about how bad of a person he is. The article went into detail about how he would curse at the director and actors and how sometimes he refused to show up for shoots or would be hours late. I never realized he was this way,I always figured he would be such a nice guy in person. Which i funny because the only actor i have ever met in RL is Will Atherton, who always plays the character of a douchebag, and he was extremely nice in person. Anyone else heard these same stories?