Comment by alentred
5 hours ago
Yes, the article seems to be not detailed enough. They show the pictures, and it is evident what the pressure release valve is, but I agree that by this logic any container or any steel water bottle is dangerous. Maybe there is some other additional feature that makes it particularly dangerous compared to other models (like, the new seal keeps higher pressure, or the lid needs fewer rotations to disengage, etc.) that is not explained here and makes all the difference. Older models didn't even have a pressure relief valve, did they?
I guess the amount of rotation needed between “airtight seal gets broken” and “lid can come off” is fairly short for these thermos.
If the difference is, say, a full 360° turn, pressure will get relieved before the lid can come off.
See also https://news.ycombinator.com/item?id=48006887. Apparently, many bottles have discontinuities in the threading to allow for that.