The various currencies found around the house are small $20 Bills,they where only made after 1929. All the currency should have been large size notes (not in terms of denominations but physical size).
Many vehicles - notably the sheriff's car and the tractor used for the harvest just after the sheriff's first visit - are conspicuously free of dust, an impossibility in farm country.
The leather gear worn by the sheriff during the trip to the farm, particularly his holster, cartridge drop boxes and night stick ring are too modern in design for 1922.
They were harvesting the corn while leaves and stalks were green. This means that the corn was still moist, so it would rot instead of being able to be shucked. Corn is harvested after it is totally dry. Oddly enough the ears in the truck were dried.
The murder at the beginning takes place in 1922 and yet the sheriff who comes to the farm to investigate does so in what appears to be a very nice 1930 Model A pickup. The Model A wouldn't even be built until 1927.
The flag of the USA in 1922 was the 48 star one, in oeration from July 4, 1912 - July 3, 1959. This had 6 rows of 8 stars in a row, all in line with each other. The flags on the hotel in open sequence had flags that resemble later 49 or 50 star/state flags with offset stars.
The movie is set in the years 1922-1925. Many of the vehicles shown were later models. For example, there is at least one Ford Model A in the beginning of the film, a model not introduced until 1927.
Several times the abbreviation NE is used for Nebraska. The 2-letter abbreviations didn't start until 1987. In 1922, the abbreviation for Nebraska would have been Neb or Nebr.
Andrew Jackson was pictured on the $20 bill beginning with the 1928 series. Grover Cleveland was portrayed starting in 1914 and would have been more likely to be on the currency in 1922.