An excerpt from the movie The Beast from 20,000 Fathoms (1953):
The guy who saw the monster is trying to convince a professor of paleontology that what he saw was real but the professor doesn't believe him.
— I don't know if this will be of any help, but you remember, doctor a few years ago, an expedition unearthed a herd of mastodons in the Siberian tundra. Dead thousands of years, yet their fur was still intact, the meat still edible.
— That's quite right, my dear Lee. But they weren't alive. That's the important difference. They weren't alive.
— I'm sorry, professor, but in all honesty, I can't support your story.
— I guess I'll go back to the hospital. Maybe I should ask for a transfer to the psychopathic ward.
— Nonsense. It's not as bad as all that, my boy.
— Thanks for listening, doctor.
I'm not sure how to properly understand the phrase all that. What does it refer back to?