Because he doesn't like killing. He craves the danger but he doesn't like the idea of killing even the dog. That's why he closes his eyes. < also most people just close their eyes when then shoot a gun.
Sherlock Holmes John Watson Jawn Benedict Cumberbatch Martin Freeman / iFunny :) <-ifunny that is not funny in any manner what so ever that is torture *sobs* >> well take my heart and throw it out the window why don't you