I don't know if your real vs fake debate is regarding CGI vs. Solid object, but here you can see the gif from another angle:
http://www.youtube.com/watch?v=nNvxFN4ji5A
Which confirms:
- The Hammer is a solid object
- The shield is fake
If the real vs. fake debate is regarding a real, solid metal filled hammer vs. a prop, then I have bad news for the people that think it is real. There is no way in the world a real hammer could be handled like that. It wouldn't even be possible to throw a hammer that size with one arm like the crewmember did. It's a real fake hammer.
On topic: