Strange thread this one.
Many thoughts of O2 vs. N2. Bar vs. PSI. I would guess neither are relevant here.
Getting back to basics, if the guy was certified he would know the basics?
The advice to always approach from front or rear is life saving. Some have mentioned, but if nothing is being done to the wheel/tyre it will sit there happy all day and night. I was always told treat it like a woman.. In front or behind work well ...but beside has the potential to ruin you. That's complete rubbish of course but you will all remember next time so I figure it's good advice.
I have not read the thread completely, but the poor guy was at the tyre because of a reported issue?
Have witnessed two tyres explode. Both on a car so we are not talking 200 psi. Mine happened after two new brand new (top branded) tyres were fitted. Drove up the A1. After a few roundabouts the steering was heavy. Stopped at the next service station and the nearside tyre measured 12 psi. Did the normal (stupid) thing and put a bit of air in. I reiterate....a bit! Way before 16 psi on the guage the thing blew up. Hot in there?
My knowledge of physics is just A-level but if the air (gas) in the tyre was very hot then the little air I added, expanded rapidly. Very rapidly on a carcass with weakened sidewalls due to the low pressure flexing for a few miles?
I didn't learn. I thought a fluke and went to the other front tyre. This time much much more gentle....still scared....but...BANG! at 14 psi.
Have never had any issues with tyres ever since but will never forget that trip up the A1.
Speedy recovery to the man concerned. Is not why we spend our time around aeroplanes.