In 1974, Daniel sees a young Charlotte running alongside her mother, however Charlotte isn't supposed to be born until July 2, 1979.
On the trek through the jungle, after the group discovers Charlotte has died, and prior to their rescuing Amy from the Others/Hostiles, Sawyer's beard changes in density, thickness, and darkness from shot to shot.
In 1974, the survivors find a style of walkie-talkie which was not manufactured until the 2000s.
(at around 42 mins) A wine bottle can be seen with the "Swan" station logo on it. At that moment (1977), that Dharma station was not built yet.
When Amy makes her first appearance in 1974, she is wearing low-cut jeans, a style not manufactured until the 2000s.
Sawyer's uniform has his surname on it - all the other Dharma uniforms display the owner's first name.