During the flashback chase scene on the dirt road, the passenger side back window of the station wagon is alternately shown as shot out, then not shot out, then again shot out.
When the two Feds call their headquarters the seal behind their supervisor says "Department Of Investigation" instead of "Federal Bureau Of Investigation." Yet, when they are identified outside of the hospital (after having been shot) to Chief Clifford, they are identified as "FBI." So, NBC created a fictional "Department Of Investigation" and then used the real "FBI" identification verbally.
When Sam, Chris, and the three bad guys are in the ghost town, the winds are high which is raising clouds of dust into the air. Connors goes into a building, and Chris runs up to that building's side to peer into it. The camera vantage point then shifts to inside looking out at Chris (as she looks in) and the air behind her is now clear with NO dust in it.
When Joe and Carol Broadhurst are at the ballet watching footage previously used in The Man with the Golden Hat (1975), the dance steps don't match the new music put under it.
In the flashback sequences for 1964, everyone still has their long 1970s style hair. No attempt is made to hide the length of the men's hair.