Well while I was at work about two weeks ago, I was attemping to pry a tire's bottom bead loose on the wheel because it was being extremely stubborn. I was using a metal bar about 20 inches long that we use to pull both beads over top of an arm to rotate that tire off of the wheel. I was placing pressure down on the end nearest me and pulling up on the far end with a lot of force (use your imagination). Then the far end of the bar slipped from underneat the tire...so yeah, I had a goose egg on my forehead for a solid two days.
In conclusion, I know what it sounds like when metal forcefully makes contact with a forehead...and it sounds strikingly similar to the bashing in that video. I would be willing to bet that it is fake for the simple fact that nobody in their right mind who committed a murder would've allowed it to be recorded (being right in front of them, that is), must less placed on the internet for all to see. But in the same token that the Halle Berry sex seen in Monster's Ball is almost as awesome as large portion of porn I've seen, this probable fake was still efficient to get a strange feeling in my gut.