We'll start with a quick refresh on skiing etiquette: Downhill skiers have the right of way. Yes, it's super annoying when you're arcing some turns down a groomer and all of a sudden rental-boots-over-jeans-guy makes an erratic 90+ degree swerve into your fall line. However, it's still your responsibility to avoid crashing into him.
Why didn't the cameraman spot his buddy's landing? Nuking into a seemingly-blind air on a busy groomer is definitely the kind of send which would benefit from a downhill spotter doing his job.