I've seen that film. Great movie. Frankly, I think Crumb is the greatest living draftsman of our time.
I saw "Crumb" in Frank Stack's comic strip class. Prof. Stack was one of the first American underground cartoonists, who contributed to Dark Horse's "American Splendor" and produced his own works such as "The New Adventure of Jesus", "Doorman's Doggie", and "Our Cancer Year". He was the man who inspired me to start inking my works.