Rundstedt-Hitler Question?

Okay, since it's June 6th I decided to pop in "The Longest Day" and watch it. Midway through the movie, I believe it's after the Point Du-Hoc scenes, General Blumentritt informs Field Marshall von Rundstedt that the panzer reserves have not been released and suggests a call from the Field Marshall to Hitler himself would get the reserve release. In response to this Rundstedt calls Hitler "that Bohemian corporal" and refuses to even crawl on his knees to him to get the panzers released. Now I already know one of the problems The Germans faced in Germany was that they had to ask Hitler to release the panzer reserve, so that's not the question. The question is is that how Rundstedt really felt about Hitler or is it something Hollywood felt would be appropriate? Rundstedt had ordered earlier in the movie to send word to Berlin to release the reserve and at that point in the movie he's angry about how the battle is progressing so it could just be something Hollywood put in, but I'm curious if Rundstedt didn't really have that kind of contempt for Hitler in real life.