The German bolt-action rifle (Gewehr 98) featured has a capacity of 5 rounds plus one in the chamber. The character using it goes on to chase Morse and fires at least 7 times and never is seen (nor do they have the time for) reloading the rifle.
The military historian Dr. Laidlaw pronounces the word "debouche" in the French manner ("de-boosh") whereas an English historian would be likely to anglicize the pronunciation as "de-bowch"; he also refers to the battle of Cannae as "c'NIGH", emphasizing the second syllable, when it should be "CAN-nigh".
The Jimi Hendrix version of All Along the Watchtower is heard playing on the radio during the shoot on the base in what is obviously summer (1968). The song itself was released on October 18th, 1968 in the UK and probably would not have had much airplay before November when the trees would not still have had their leaves.
When Farridge, the photographer, is snapping Jean Ward as she poses on a tank, he tells her to "think Warren Beatty". However, he pronounces the actor's surname in the British manner, as "Bee-ty", whereas the man himself has always pronounced it in the American way, as "Bay-ty", something about which he was always keen to correct British interviewers.
In Season 1 Ep. 4 Morse is shot. Explaining the limp John Thaw has in 'Morse'. This has been mentioned a number of times. However in Season 5 Ep. 4 he is shown running through the woods and across a minefield while being chased by the 'bad guy'. No limp. No indication of any kind that he had ever suffered an injury to his leg.
The "tank" used in the photo shoot is an Alvis Scorpion, Combat Vehicle Reconnaissance (Tracked), CVR(T) which was introduced into service in 1973.