Factual error: The blue Volvo 240 Philip and Elizabeth occasionally drive in season 5 (1984) is from 1986 or later.
Continuity mistake: Philip sustains a stab wound a little right of his stomach area but there is no scar in subsequent episodes.
Continuity mistake: Elizabeth sustained a fairly severe wound to her back (left side, if I remember correctly) a little above her waistline, but no scar appears in subsequent episodes.