Replying to Funniest thing i've ever seen happen to someone

me and my friends were making a mountain bike video for school. we went up on our towns local mt. we were about to shoot a scene where myself and my friend r riding down a hill.(sounds lame but it was the closing scene.)one of my other friends who was also on location planned it so the other kid riding with me would be on the inside, closest to the woods, so that the kid not riding could jump out and drop-kick him.well, as we r descending the hill, the guy in the woods trips over a log.even though he didnt touch the other rider, he still scared him...and made him flip over his handle bars.when he got up...he proceeded to say,"damn it...MOTHER FUCKER" (we had cell phone music in the background, so it was a little hard to make out.)even funnier, we actually had to show this to the teacher as our project.