Stuck throttle cable

My friend has a 2002 Grizzly; it works really well.
He has none of the problems others have posted.

However this weekend, his throttle stuck wide open. He almost ran over his own kid, hit his trailer, and then hit a tree, not to mention a couple of scrapes and bruises.
No one was seriously hurt. The bike faired rather well other than a $140 Cdn bent rim. (ITP's)

On closer inspection we found that his throttle cable was being pushed and kinked by his Yamaha brand and installed hand guard brackets.

Has this happened to anyone else?

If you have hand guards, please check your cable.
It was not a pleasant situation to see.