Joaquin----- Were you acting or were you stoned????

I happen to like Joaquin Phoenix but I was very shocked when I watched the video of him on the Letterman show. He was like someone from outer space. He couldnt answer the questions properly and was very inappropriate. How can an actor go on TV and act like a complete idiot??? Some people think it was a publicity stunt. I personally thought he was acting, but who knows, he could have shot up or smoked something wacky. I remember when Farrah Fawcett was on the show years ago. She acted totally wacky too but I think she was bombed from the booze! Letterman, I must say really made me laugh talking to Joaquin. I really hope it was all an act- I would hate to see Joaquin wind up like his brother River.