Well I'd imagine he wouldn't be suspended if it was an actual policy.
I never worked for Care, but amongst the So Cal private ambulances, they're generally have a better, more upstanding reputation than the generic, fly by night, dialysis mobile companies.
Before they shut down, I spent a few months at Gerber Ambulance in Torrance, and we were required to respond Code 2 (no lights, no sirens) to every call while Torrance FD responded Code 3 to everything, so by that 95% of the time TFD was first in scene, and there were persistent rumors that in those cases where Gerber was first they were supposed to sit and wait.... but those few times we went in and initiated Assessments and treatments and never once got grief from TFD or management, so as far as I'm concerned, those rumors were just that, rumors.
I also worked McCormick with LA County, and LACo never had any issues whatsoever with us being first on scene and initiating treatments. While they are a big department and the different regions can develop different cultures, I can't imagine the regions where Care responds developed that "Don't make scene without us" type culture.
As far as Orange County Fire Authority... all I can say is I've heard stories thru the rumor mill that OCFA liked to be on scene first....
But I have never worked in Orange County, never even really met any OC Fire guys so I cannot verify any of those stories.... but given my other experiences with these rumors, I'm gonna assume they're also false.
So I'd some Care EMTs do still believe those rumors, and they are indeed false, that Care, and the Authorities Having Jurisdiction they work for, want Care to start Assessments and treatments as appropriate when first on scene, and your buddy did not do that... then I can very easily see why he got suspended.
So yeah, the mere fact that he got suspended tells me that Care does not actually have any policies that say "sit and wait for Fire" and your buddy was in fact expected to go be an EMT and not just an ambulance driver...