False. This situation was entirely avoidable.
Both parties share some blame, but the snowboarder shares a higher proportion of the blame.
Skier Responsibility Code
[*]Always stay in control, and be able to stop or avoid other people or objects.
[*]People ahead of you have the right of way. It is your responsibility to avoid them.
[*]You must not stop where you obstruct a trail, or are not visible from above.
[*]Whenever starting downhill or merging into a trail, look uphill and yield to others.
[*]Always use devices to help prevent runaway equipment.
[*]Observe all posted signs and warnings. Keep off closed trails and out of closed areas.
[*]Prior to using any lift, you must have the knowledge and ability to load, ride and unload safely.
Prior to the main collision, the snowboarder had a VERY near miss with another young girl. He was not entirely in control of his self in this situation and obviously was unable to stop or avoid people or objects in his path. Now the father did appear to have his son start downhill without looking uphill and yielding, but that does not mean that the snowboarder has a free pass on item #2. It is still the uphill skier's full responsibility to avoid them, and if in full control and skiing in a responsible manner, this is a non-issue. The only time I'll side with the uphill skier in a collision is when someone is camping in a landing in the park.
If you are cruising a trail and come across a congested section, ESPECIALLY when it is young children, ease up and slow down. Young kids don't always ski predictably and is creaming some little kid worth it?