Chris correct me if I am wrong... but Star EMS helps AHFD by providing 3 basic transporting rigs (1 for each station) and 1 medic to man the Alpha rig at Station 2 (Alpha 2). If Auburn Hills gets real busy the can then call Star EMS for extra Alpha rigs or use the Mutual Aid agreement with surrounding dept (Rochester Hills or Oakland Twp). It is a real neat system and seems to work well. AHFD has been doing this for a while all the way back to when AMR used to be in the area.
That's essentially the way it works. They have three BLS ambos in the stations that are manned by the POC EMTs. They're modular rigs, and marked as Star, with the exception of AHFD decals on the doors. Alpha 2 is actually owned by the city, and marked accordingly. Their Engine 2 is also licensed as a non-transporting ALS unit for second calls. They can call us, or Rochester Hills for ALS fill-in, not sure who else they have MA agreements with. We can also use them in a pinch for MA into Orion if it really hits the fan.
The concept was created between the city and AMR. The city got an ALS fire department for about half of the start-up costs (back then, AMR provided all of the equipment, the rigs, licensing, etc); AMR (and now Star) does the billing and gives a portion back to the city.
For what it's worth, the medical/paramedic first responder system that Troy PD/Alliance use was originally set up by Paramed. I was one of the original MFRs in Troy. That was another system where we had authorization to use frequencies assigned to either PD or FD, and we used them quite a bit.
As far as the CEMS radio traffic, could be an accidental oops (picked up the wrong mic or they could be using Novi dispatch times to help fill out the run sheets.
I don't think it's accidental, I hear it several times a night.