In the pilot Elaina says that she always liked David's Mother. In "Homecoming" David's Mother died when he was a young boy.
As the Hulk runs from Helen's house, his wig blows in the wind. Lou Ferrigno's black hair is visible; also the top of his ear has no green makeup on it.
When David hulks out in front of his sister, the footage used during David's second stage of change was from The Beast Within from Season 1. The zoo patch on David's shirt can clearly be seen.
When David leaves the house his father gives him his bag which has a jacket across it. It is a light brown colour. As he walks away on the road on the next shot he is wearing a blue coloured denim jacket.
The length of young David's hair in the flashback sequences is appropriate for a 1970's kid but not for a boy in the 1940's.
When David turns into the Hulk on the Plane his father says "David, My God" his mouth is not moving.