During Sir Walter Elliot's opening soliloquy he records the date of his marriage as July 15th, 1784 shortly followed by the birth date of his first child, Elizabeth, as June 1st, 1784. The latter date should be 1785 (per the original text).
During the concert Anne Elliot uses a poster for the event as a means to translate the Italian lyrics into English - the same poster for both songs.
Walking down country lane, actors pass WWII tank traps.
Some of the female extras, in the tea room and at the last party, are wearing modern (1970s) style makeup, i.e. false eyelashes and rouge/blusher. The comparison is stark between them and the main protagonists who were not wearing obvious make-up.
Shadows of the boom microphone and/or camera move across the players throughout the indoor scenes.
Lady Russell addresses Sir Walter to his face by his christian name with no title - which is extremely unlikely. Etiquette would demand that she address him as "Sir Walter" just as he addresses her as Lady Russell.
After Anne's arrival at Uppercross during the first conversation she has with Mary the latter recounts a dinner outing the previous evening at the Poole's. She says she was crushed in the Musgrove carriage as the senior Musgroves (her in-laws) are "so very large". Noel Dyson, who plays Mrs. Musgrove, can hardly be described as "very large".
During the first visit at the Harville's in Lyme Mrs. Harville addresses a comment to "Miss Musgrove" but Louisa responds. "Miss Musgrove" would be the eldest daughter of the family with all younger sisters addressed using their christian name, e.g. "Miss Louisa". You can see that Mel Martin (the senior Miss Musgrove) was about to respond but Zhivila Roche (Miss Louisa Musgrove) incorrectly butts in.