I'm suprised he was able to throw the scissors accuractely enough to hit blades down (Looks like he was too).
Also, from the looks of it, those guys weren't very good friends (if friends at all) and the dude antagonizing him totally deserved a pair of scissors to the arm.
Puncture wound, with the shape of scissors there would have been atleast some initial blood seepage, it is all too weasy to replicate something like that with derma-wax or latex, it ~could~ be real, but they is a far greater chance of it being fake.
I work in a theatre and am a fully trained makeup/special effects artist as part of a course I have done, we used to make shit like this to freak out people, really aint hard.
I'd say it's real. Have you ever been stabbed? If you make a clean cut blood doesn't come out until you remove the object that went into your body. Plus that guy doesn't seem to be that good an actor to display shock as well as he did.
I've been cut by scissors before in middle school and believe me, it was messy. Besides you'd have to have a crazy amount of force for those scissors to go that deep. If it was real, it would have touched bone.