I’m glad we agree the snowboarder has failed. I think all other discussions points have a much less significant impact on safety and are therefore a distraction that hinders safety.
My opinion is that looking backwards rarely avoids collisions. IMO the kid is skiing throughout the clip making it impossible to look forward and backward at the same time.
I think a better analogy is: I am stopped at a stop sign looking for traffic to clear so I can turn. While that is happening someone rear ends me. And you have the audacity to say I should have seen the person behind me and avoided him. Rarely is such avoidance feasible. If I had focused on what was behind me I likely would have pulled out into traffic and been hurt/killed.
Lets focus on what clearly can make a major impact on safety which is teaching that the snowboarder's behavior is unacceptable rather than other scenarios that may have little if any positive impact.
I think your analogy is a little off. What most are saying with respect for the code is that if your waiting to make a right turn at a red light, you stop and look before proceeding out into traffic. Or a better analogy is a 4 way stop sign. If you stop at the intersection you look around before proceeding, you don't stop, stare straight ahead, and then drive through the intersection. That is what the intent of look uphill and yield is all about.