Your own quote is literally the benefit of the doubt I'm complaining about, it's not me failing to understand something here.
Cop was way wrong here, clearly. Why are you talking about obviously forged documents, what does that have to do with this situation? You're saying because of other situations, you can see why the cop is suspicious, and that's normal and fine - he just should've checked properly! I realize I put words in your mouth, but they sound like the ones you're saying.
That's you extending benefit of the doubt. I'm saying that cop much more likely didn't really give the first fuck whether it was legit or not, and that's the kind of doubt that must be extended to such people.
As in, "Think that cop mighta been doing the right thing in this case or at least with good intentions? Nah, prolly not". Unless I really am misunderstanding, you're doing the opposite.
You're doing the opposite. [Edit - whoops - struck out line was a duplicate I left accidentally before adding the "Unless..." above, which does happen to create the exact opposite effect intended by adding the "unless" in the first place]