Going off my somewhat fuzzy memory: Earlier in his career Hollywood kept having trouble adapting his stuff for the screen, despite him writing crime and western stuff that you'd think would make the transition pretty well. There was an anecdote about Leonard visiting the set of a film based on one of his books, and one of the actors came over during a break and asked him "How's it feel to hear people fucking up all the dialogue you wrote?" His experiences dealing with Hollywood inspired Get Shorty (the Danny DeVito character was based on Dustin Hoffman) which became the first of his stories to become a successful movie, after which he had better luck.
I haven't read anything of his in a while. In his honor I'll add a couple of them to my increasingly speculative to-read list.