I tried to get to the point that no vet wants to give the VA an alternative explanation for any disability they are claiming besides military service. The VA will ignore ten tons of evidence that supports service connection if they can jump on one sentence that could be the explanation for a disability that is not related to military service. This happened to me more than once. If you give the VA a string to pull on they will pull that string and unwind your claim.
John, I hear you...I had the same issue come up for me in the early part of my claim process back in 2003. I think that is when it turned into a "fight" with the VA. So, I know exactly what you're talking about.