My first EMS job was with a private 911 agency that covered numerous municipalities. One of them was a very small (few thousand residents) city with a non-transporting BLS fire department that responded to every medical call in a squad truck.
Per our contract with the city, we couldn't respond to any call until the FD requested us. Didn't matter the nature or urgency of the call, or even whether we were closer, or that we went to every call they went to anyway because we transported every one of their patients. We'd hear them get toned out by the county for an obvious ALS complaint (asthma attack, chest pain, etc) and have to sit on our thumbs until the FD EMT-B's got on scene, assessed the patient, confirmed whether ALS was actually needed, and then requested an "ALS transport" or "BLS transport" as well as the response mode. They would tell the patient which hospital they were going to and what interventions, if any, they would have performed enroute.
There were many times that ALS interventions were needlessly delayed by these guys arriving first and playing on scene (er, I mean, "assessing the patient") for 5 or 10 minutes before requesting us. Predictably, our paramedics often disagreed with the diagnosis and treatment plan decided on by these EMT-B's, and it was a constant source of friction between the two agencies. Things only got worse when the agency went "EMT-I", because now these guys REALLY thought they knew what they were doing, and the delay between them arriving and them requesting us got much longer because now every patient was "ALS" and they pretty much refused to allow us on scene until they had an IV started.
It was a terrible approach to EMS which put the well-being of the patient exactly last, and unfortunately it wasn't an uncommon set up in this region. I also worked a fly car for the same agency in a very rural area covering multiple rural municipalities with whom we had similar arrangements.
Point is, I wouldn't assume that just because a new paramedic says he's having trouble with a BLS fire department, that it's necessarily because of his attitude.