When Sam is in the basement with Michael and Johnny, Michael mentions that he and Johnny were planning to escape in a tunnel which would lead to the 63rd St subway which would take them to Penn Station. The 63rd St line did not open until 1989 and does not go to Penn Station.
At the hospital, Sam leaves a modern elevator with LED-display.
A television commercial was shown for an AMC Pacer. American Motors Company didn't introduce the Pacer until 1975, and the model shown was a 1978 model.
The helicopter seen flying at about 26:35 is a Bell 222 which only made its maiden flight on August 13th 1976 (i.e.) just under three years later.
During the party, Ray Carling carries a Polaroid SX-70 camera with a Sonar auto-focus around his neck. The Sonar feature of the SX-70 wasn't introduced until 1978.