I'm surprised no one has mentioned the incident where he had a serious car accident in Hollywood (might have been in the late 30's, but could have been during They Were Expendable) and was rushed to the ER. They didn't know who he was, and a knife-happy quack wanted to cut his leg off, but a VERY alert orderly spoke up and advised someone to call the studios, whereupon someone came down and stopped the amputation from occurring!
That occurred during the filming of They Were Expendable.