Revealing mistake: When Utah is fighting Mr. Nixon at the gas station, the two land on some fire and catch fire. The flammable gel on the back of Mr. Nixon's jacket is briefly visible. (01:06:55)
Revealing mistake: When Angelo is shot in the back at the airport, you can see a pack underneath his shirt when he is rolled over by Utah. (01:39:44)
Revealing mistake: During the night surfing scene notice that the sun is evident in the background (look closely it does not appear long). There are also shots where you can see clouds and faint blue sky. Moments later you see Keanu and Lori sitting in the water with completely different lighting which was actually taken at night and further distinguishes that the surfing shots were not actually done at night time. I heard the scene was shot during the day with a filter so it looked like it was shot at night.
Answer: He is listening to music and just getting getting really into it.
Toolio