Henry is really into riding his bike. Now on a normal day when he is on nice flat ground, he wears proper brain protecting equipment. On a day when he is cruising down hills? Well, no not so much.
We're not quite sure what he says when he initially ends up in the bushes, but after he says, "I don't want to go fasser and fasser."
Now the real question is: Did he lose control and end up in the bushes, or was he smart enough to use the bushes to bail out on his wild ride?