I can't tell if this is really funny, or just plain mean!

As one guy is working on a car, the other is using a chainsaw to cut some boards. As the chainsaw guy puts down the real chainsaw, and switches to one without a blade, his friend is none the wiser.

That's when he fires it up, and puts it up to his chest so it appears the blade has gone through him. Along with that, there's fake blood involved, and he falls backward.

The "friend" that is working on the car turns around, and sees what he thinks is his friend with a chainsaw through his body, and immediately screams, and his body shuts down.

That's quite obviously true shock, as he passes out, and even twitches.

Is this funny, or just plain mean?