I have heard that they don’t get along very well, even the MP’s and the SDPD get snippy with each other all the time I have been told.
More likely the Oceanside PD, Carlsbad PD or SD County Sheriff...maybe even the CHP...but, yes, they don't get along well.
I have some personal experience that I won't get into, but my assessment is that many of the cops have a chip on their shoulder...