By training I am a radiation physicist and actually do know about particle beams hitting people. The LHC beam would certainly give someone an appreciable radiation dose, although the secondary synchrotron X-rays would probably be worse than the proton beam itself. In fact a much lower energy proton beam would have a worse effect on your hand/body, since that beam would actually stop inside you (protons deposit most of their dose at the very end of their range).
Of course the injury you received would largely be determined by the length of time your hand was in the beam. Really not fun results can be radiation ulcers or radiogenic cancer. If the dose were high enough you could get a radiation syndrome, where some/all of the fast growing cells in your body die off and you die in a few days or months.
The only data I could find after a quick search indicated that the dose present in the beam line would be on the order of 10^4 Gy per year. That means if you managed to put your hand in the beam for 1 minute, you're only looking at about 0.01 Gy, which isn't that much.
There's actually a reported case of someone getting hit by a proton beam on the head in 1978:
Bugorski was leaning over the piece of equipment when
he stuck his head in the part through which the proton
beam was running. Reportedly, he saw a flash "brighter
than a thousand suns", but did not feel any pain.
In case people take what the first person in the video says combined with your quote from wikipedia but don't read the entire wikipedia page I'll quote this:
The left half of Bugorski's face swelled up beyond
recognition, and over the next several days started
peeling off, showing the path that the proton beam
(moving near the speed of light) had burned through
parts of his face, his bone, and the brain tissue
underneath.
My work is indirectly related to proton beams. Your comment about energy deposition in human tissue reminded me they can be used for cancer treatment that's localised to a certain depth. In fact http://en.wikipedia.org/wiki/Proton_Beam_Therapy would go some way to answering the original question about the interaction between the LHC beam and a human hand. Presumably we can take it as given that there is some sort of exit window (not sure what material would be best?) from the beam guide into the air.
Aside from the bremstrahlung, proton beam interactions with matter include spallation from heavy nuclei (giving neutrons) and the formation of muons. Both of these would deviate from the original proton beam direction and irradiate other parts of the body.
Of course the injury you received would largely be determined by the length of time your hand was in the beam. Really not fun results can be radiation ulcers or radiogenic cancer. If the dose were high enough you could get a radiation syndrome, where some/all of the fast growing cells in your body die off and you die in a few days or months.
The only data I could find after a quick search indicated that the dose present in the beam line would be on the order of 10^4 Gy per year. That means if you managed to put your hand in the beam for 1 minute, you're only looking at about 0.01 Gy, which isn't that much.