Factual error: Klinger says he would wear Hula Hoops(R) in his ears if it would get him a discharge. For several reasons, he is using a phrase that does not yet exist:1) Show wise, Klinger will later try to convince Charles to invest in developing a new toy, a hoola hoop like plastic tube, being inspired by Korean children playing, and 2) plastic hoops which came to be called Hula Hoops were only introduced by Whamo in 1958. Setting episode dates is always difficult for MASH, but the Mash Olympics (inspired by the 52 Helsinki games) are still to come so we can say it must be 52. 3) The Hula Hoop trademark was only registered in 1962 to Whamo. No info. as to what name the hoops were marketed under prior to 62, but Klinger is using a term at probably ten years, at least 6 years, before it came into use.
Other mistake: After being loaded with wounded, an ambulance accelerates, turns left and moves out of sight. Immediately after there is the sound of a crash, and the ambulance is lying on its left side. Radar states that it turned too fast and rolled over...but in that case, it would be on its right side.