if this was in my country both aircraft would have been on the Berkley co "advisory frequency
There is no regulatory requirement in the US to be on any frequency when operating into/out of an uncontrolled airport, in fact you don't need a radio at all in such case. I don't have the map in front of me but F-16 pilot certainly had no reason to be on Berkley's CTAF (or sometimes called Unicom) frequency when practicing approaches to adjacent airport, he probably was tuned to the other airport's tower or approach control (sorry, I didn't read the thread from the beginning). I am not sure what this F-16 was practicing however - if you shoot a practice approach and weather is VFR you must look out and still rely on see-and-avoid method, being IFR doesn't relieve you from this duty, so unless you have another pilot, you really can't practice IFR in VFR weather. If this was pure class E airspace and weather was VFR - both had right to be there and both had to use their eyes.