When young Nucky confronts his father, he throws down his hat and coat. When he picks up the coat later, the hat is gone.
During the episode, when Joseph Kennedy, Sr., is conferring with United States Senators, it is implied that JPK, Sr., learned a common phrase "while in England." JPK, Sr., indeed was the US Ambassador for England in the late 30's and early 40's, until dismissed by President Franklin Roosevelt. The problem is that JPK, Sr.'s discussions with the United States Senators took place in the early 30's, when JPK, Sr., was a Hollywood producer.
The first meeting with the Commission is confabulated. Al Capone (Steven Graham) in real life attended the meeting. He was indicted on tax charges several months after. Also, the meeting did not take place in Atlantic City, but Chicago.
Tommy had no way of contacting Gillian who had been locked up in a mental institution for the last several years so he wouldn't have known what Nucky did to James. The whole idea that Tommy was getting revenge of his father didn't really add up because he had no way of knowing since he wasn't being raised by Gillian and had no way of even contacting her.