oxygen, harmful or not?

Im pretty sure oxygen is a good thing, in the majority of cases anyways. In the last 24 hours I have had 2 encounters where I thought a bit more O2 would definitely be a good thing, but was contradicted by providers with more schooling than me.

event #1:  severe asthmatic comes in to the ER and we take them straight to a bed, I pull out a duoneb treatment (cause it takes respiratory a few min to get downstairs after someone calls them) and give the pt a neb via mask on oxygen when the RN tells me "no, use the medical air"...what?? When she sees my confused look she says they normally use medical air, and I inform her we (the medics) use oxygen, pt got the neb via oxygen in the end....

event #2: 20 something y/o male, intoxicated, took a swan dive head first 6-7 feet into a cement trench. Pt unconscious and unresponsive, lac to right temporal, no active bleeding, pupils round, equal, but non reactive to light, pt breathing 12 times a min but shallow with snoring resps, lung sounds clear and equal, O2 sats at 02%, pt resps assisted via BVM, when OPA was attempted pt clenched down. 2 large bore IVs established,  24 min from on scene time to completing extrication of pt from the trench via stokes basket. Upon arrival of flight crew I asked if they wanted to RSI and they replied "no, he's breathing on his own".

I dont know if they were concerned with increasing the ICP, but found it interesting they opted not to intubate. Follow up of the pt was pt had an open fx to right temporal area, several closed fx, an epidural bleed to right temporal lobe and a parenchymal hemorrhage.  Pt was intubated at trauma center upon arrival. Pt was extubated approx 8-10 hrs later and is now alert and oriented but still in ICU at trauma center.

What do you all think?