Anecdotes

Sir Michael Caine saw a lot of himself in the character of Harry Brown, they're both combat veterans (Harry is a Marine who served in Northern Ireland, Caine served in the British Army during the Korean war), and Caine lived in the same area that Brown does. It was things like these that drew him to this movie.

The woman singing "Gold" in the pub was the unit nurse on this movie.

When Harry is going through the items in his "treasure box", he pulls out a knife. It is a Fairbain/Sykes knife designed for knife fighting, especially for military commandos in World War II.

The song at the end of this movie is called "End Credits", it is by Chase and Status featuring Plan B (Ben Drew). Ben Drew played Noel Winters in this movie.

When Harry Brown (Sir Michael Caine) taunts the criminal gangster and drug dealer, Stretch (Sean Harris) after shooting him during the climax of the film, he tells him he's probably been shot through his liver and explains how near death he is as a result.

But the wound is shown in his lower left abdomen, while the liver is in the upper right, just under the edge of the rib cage.

Any abdominal wound would be terribly painful, but most tend to be survivable unless a major artery is compromised. Because there is a major artery running through the liver, a gunshot wound to that organ is extremely dangerous and requires immediate attention, but wounds to the intestines are much more readily survivable, assuming the patient gets treatment to prevent infection. The wound that Stretch is suffering would be much more survivable than Harry Brown is letting on.

A Royal Marine combat veteran, as Harry Brown is, would know that, but he is taunting Stretch.