...As Tech pointed out above, it was less to do with the high pressure and more to do with the fact that in an oxygen rich environment, any solvents present in the firing mechanism of the airgun would have become highly explosive, it's an accident waiting to happen.
Looks too powerful/rapid even for controlled use in a hybrid cartridge,
it could have two chambers seperated by a burst-disc,
One with a drop of gas or oil, Other high pressure oxygen,
And a pin to rupture the burst-disc between?
D*mn shame (word of the day) it wouldn't have needed any spark (?)
Guess now I know why the automotive world uses more expensive N2O rather than cheaper oxygen for racing!