You've overstepped. I don't think anyone brought into question your profession or academic ability. Don't fight dirty just because you aren't getting the result you want from the case you are laying out. Instead, look at the case and adjust. You obviously haven't laid out a compelling enough case.
As for the video - the dude is a resident. Since you seem to like to explain things that don't need explaining, let me explain. He is still in training. Has graduated medical school (good for him) and is now working as a physician under the supervision of more experienced personnel while he continues to gain knowledge and experience. He also talks a lot in maybes (like you have). Maybe the puck hit the neck and severed the artery. Maybe it fractured the temporal bone. maybe, maybe, maybe. He has no data, no evidence, no facts to hang his argument on. And like you, even hypothesized that a full cage might have mitigated the injury, but probably not. To his benefit he makes the obvious statement that 100s of thousands if not millions of folks have likely been hit with a puck in a similar area of the head, with very few (if any) of them seeing the catastrophic outcome this young man did.
I think the point has been made before, we can't eliminate risk, only hope to mitigate it. Maybe a better helmet design could further mitigate the risk of this case, but the question is "is it worth the effort considering how prevalent serious injury is?" That is the question CCM and Bauer and Warrior are all asking themselves right now. What is the Return on Investment if we explore designing a safer helmet to mitigate these types of injuries? Considering the amount of merger and acquisition we've seen in the hockey equipment world over the last 20 years, I have to imagine margins for most equipment is razor thin. Throwing a ton of money into a new helmet design would make those margins even thinner and could potentially sink a company if they aren't careful with how they approach it. Hate to break it to you, but at the end of the day, staying in business is their top priority, your safety is further down on their list.