If you thought the fight scene seemed maybe 'too real' it's because it was. Shane Meadows, the director, held Woody in exile, from any of the other cast members on set. Meaning, when Woody bumped into the gang his reactions where completely real as he actually didn't know any of it was going to happen...
The scene where Milky and Woody have a fight, was shot in only 1 take! And was completely improvised.