This takes the type of guts--or stupidity--we can't even imagine.
While we don't know anything about the jumper, it seems hard to believe he's a complete amateur. If he is, that backflip's got some pretty good form.
One way or another, as one commenter put it, this is definitely on "the thin line between bravery and stupidity."
This summer, "balconing" repeatedly hurt British tourists who would jump between hotel balconies in Majorca.