I do believe these were injuries requiring medical attention.
Snowboarding has a long documented history of having a slightly more injury prone rate than skiing based on per user day. All that data you are looking for is contained within the ski injury site. I can only lead you to water...
Looked all over the article and google searched the Journal Article mentioned but found no data. Nevertheless, even if you have a high injury rate per user day of snowboarders vs. skiers, there are still too many variables to say snowboarding is more likely to injure you.
I'm guessing that the skier demographic is on average older and potentially more conservative than snowboarders.
What I don't like is that someone may reach the wrong conclusion reading these stories. If you're just looking at getting into snow sports, and see these articles, you may be inclined to think that you're more likely to get injured learning to snowboard than learning to ski. But this article, and none of the stats I've ever seen can reach that conclusion. I highly doubt there's ever been a controlled study, of an equal sample of people learning to snowboard vs. an equal sample of people learning to ski (ie. same age, physical ability, comfort with risk taking, etc.)
The articles can't say that "person X" is more/less likely to injure themselves in one sport than the other, all they can say is that the average snowboarder
is more likely to injure themselves than the average skier
. It's an interesting statement but at the same time doesn't really say anything.