Your right police are experts in firearms just like the 37yr retired Lieutenant General of the Army who said the AR-15 has "full semi-automatic." If it comes from a higher authority it must be factual. It's all speculation at this point since none of us was involved in the seizure.
Just because the BRPD and the Lieutenant General of the Army both wear uniforms does not mean they must share the same knowledge, or lack of knowledge, of firearms. That's a logical fallacy known as a weak analogy. Two things sharing one property does not mean they share a different property. And I'm not saying it's factual because it comes from a higher authority. (That's a fallacy aptly named appeal to authority.) In fact, I haven't said it was factual at all. All I said was the reporter said it came directly from BRPD
No, none of us were involved in the seizure. The only thing we have is information relayed from someone who may be more knowledgeable than any of us. But not being able to prove the information is true is not proof the information is false. That's a logical fallacy called argument from ignorance. Incidentally, your initial claim looks like a special case of argument from ignorance called argument from incredulity. That's when you claim something is false because you don't understand it or don't believe it.
Do you want to try again? Or are you willing to stipulate there is no information available yet to accurately say the information supplied by BRPD is factual or not? I'm good either way. I like playing the "guess the fallacy" game.