You should not, obgraham -
xxx
You know, we all learn from each other here, even a lot.
And when you, or someone else does not agree, let us say it in the clear.
I am just a pilot in charge of pilot training where I work.
And I teach following my curriculum, and the manuals I have...
My O2 knowledge comes from a USAF manual "Your body in flight" - 1963 edition.
They gave us that book when student pilots had to go through the pressure chamber.
And sometimes, I learn from others... even from classroom trainees.
All the best to you -
xxx
Happy contrails