I'm not sure if Robin Williams died for any other reason that he was depressed and he killed himself. Anytime when a famous person dies, their movies/products/anything involving them goes up in sales. Look at Michael Jackson, Elvis Presley, and Lucille Ball. You can see after their deaths, there was an uptick in the sales of their products. It seems to stand to reason; a focus on them from the media in their passing, and it brings attention to their lives and what they did.
Not sure if Robin Williams was executed or murdered or whatever. I thought I it was suicide.