I had one of my German colleagues watch this and he was laughing as he
explained what was going on. The juggler wants to make a commercial
for a Eurpoean building goods store, similar to our Home Depots. (I
can not recall the store's name) He wants to teach customers how to
use tools such as the hammer. My friend said "He can't do that"
before the first hammer struck the nail head and was then amazed as
the nail went "home" and then the hammers were made to stick in the
beam.
We still can't be sure if any trickery went on here but we all agreed
that the nail was position in a hole so minimal force would be needed
to drive it in. Regardless, if the video is unenhanced, that guy
drives nails better with his hands off the hammer than I do with mine
on. No way would he hit his thumb doing that.

Marc