Factual error: The concierge in 1968 rushes to help a guest who is choking. The scene depicts him performing the Heimlich Maneuver. It was not introduced until the 1980's.
Factual error: In the scene where Jeff Goldblum collects his dead Persian cat from the coat check girl, the cat appears to be bagged in a plastic bag. Plastic bags were not yet in use at the time this part of the story is set in (the 1930s).
Suggested correction: In none of the shots in the scene does the bag appear to be made of plastic.