What it comes down to is vetting instructors and determining whether they are qualified to teach not only the overall subject matter, but specific points within that subject matter. We have to separate the "instant credibility" that comes with having a specific title (i.e. being a veteran or cop) from actual legitimate credibility due to experience, training and empirical studies/education.
There is something to be learned from learning how to fight around a vehicle, but if someone were make claims that it would be directly applicable to LE patrol duties, there is an added level of qualification needed to make that a credible and efficable skill or skill set. The fact of the matter is that a SOF trained veteran may have significant training and experience with offensive vehicle interdiction related to shooting at, out of and vehicles, and they may know how to mechanically disable a vehicle and forcefully extract an occupant. They would also likely know how to do this better than a LEO. In contrast, a LEO has far more expertise with "soft" contacts and interdiction, general traffic stops, vehicle-based investigation and inspection, and functioning independently in and around vehicles. A SOF/.mil guy trying to tell a cop how to do a traffic stop or how to survive the most common types of officer ambushes is somewhat misleading without having some other base of information beyond SOF training. This works vise-versa for a cop trying to teach say, four SOF guys how to de-bus a vehicle and engage multiple waves of attackers. Quite simply, there's a stark contrast in TTPs.
We also need to realize from all sides of the fences that our specific background may not be the end-all of knowledge on all subject. Being both a former .mil and current .le guy, I know this all too well. I am sick of .mil people being given a pass as being gun experts and tactical and shooting experts. I am also sick of this same pass being given to cops who don't have the qualifications and training to back it up. In this instance with vehicles, there are certain aspects that have carry-over. Certain aspects, however, do not. The trick is determining and accepting which areas do not have universal applicability.
Simply put, you have to look at what is being offered as the subject matter taught, and what realm the instructors have experience in. When someone steps out of their lane, they need to explain their actions or words. If they can't, they legitimately deserve to be called out on it.