I think it means: they said there was a gun because that's what they had been told; of course they couldn't have known for sure, not having been present at the time; yet why should they lie about having been told there was a gun?Of course, had JG stated it in this fashion, there would have been no argument.
I am starting a new thread. This one is over 1000 posts long, and is too unwieldy. I'll try to ping everyone.