"I didn't realise it was such a big deal. About a week later I heard they were going after Robin Williams and Jack Nicholson."
And Lithgow is spot on. The producers did indeed chat to Robin Williams about playing the Joker but they had an ulterior motive for doing so.
As Comic Book Legends Revealed wrote in 2014, they approached Williams "only to compel Jack Nicholson into taking the role ... It worked, as Nicholson quickly signed on after they started talks with Williams".
Williams was a huge Batman fan and he was understandably angry about being used as a pawn in negotiations.
Speaking to Empire in 2010, Williams said: "The Batman films have screwed me twice before. Years ago they offered me the Joker and then gave it to Jack Nicholson, then they offered me the Riddler and gave it to Jim Carrey."
Both Lithgow and Williams missed out on a huge payday. Jack Nicholson was paid $6 million for playing the Joker but also negotiated a percentage of the film's profits and merchandise sales.
According to Entertainment Weekly, Nicholson eventually walked away with more than $50 million.