That's why I won't ride dirt unless it's a one way trail. I'm not good enough to avoid those types of things.
Lots of folks claim that they'll avoid crossing the center line at all costs even if it's clear, the problem is that sometimes they crash trying to salvage a mistake to hurriedly or harshly. The guy in the second video did the right thing, cross, recover, get back ASAP. Even though that was close and probably raised the radar of both riders it's better than him crashing trying to avoid the center line making a bad situation worse and possibly taking the other bike out in the process.