Other mistake: When he puts the 2nd can of dog in the bowl it's just a rerun of the 1st can being dropped in a bowl.
Factual error: As someone already noted, the Boeing 747 didn't enter commercial service until 1970. In addition, the Pan Am 747 type shown flying the characters back to the U.S. never existed. It has the extended upper deck common to the 747-300 and -400 series (introduced in the 1980's) but with only three windows (common to some -100 and -200 types). Also it has higher bypass engines which came later.Verbal
Character mistake: In the Western scenes, when the characters are wearing spurs, they have the spur straps buckled on the wrong side (inside) of the foot. Spur strap buckles are supposed to be on the outside, not the inside, of the foot. Since it's wrong in every scene, it might be a comment on the TV show itself having low attention to detail.