It's just missing some pages...
The Flamethrower is one of the 3rd person weapons, like the detachable turrets and the Missle Pod.. those aren't listed either... or the deployable weapons..
Well we should be grateful that we're even privy to seeing these scant few pages, but I'm sure some people are irked that they didn't get the whole thing... well beggars can't be choosers..
It's a leak, not an official release.