The AHJ approved that

This is the vent from a fairly new furnace (<2yrs). Was showing the buyer and the seller jumped in and said, “that is not a problem, the building inspector looked at it and said it was fine.” I told the buyer, he is right, the AHJ rules, but unfortunately, it does not mean they always know what they approve. It is not safe and needs repair. 13 in. and 16 in. from the corner (which means 20 in. along the pipe).

Bad enough when homeowners screw it up, but then the AHJ goes right along with it. Frustrating.

Of course, you don’t actually know that the building inspector look at it, so it’s hearsay. Really only three ways to determine if the building inspector looked at it: (1) You were there with the building inspector when s/he looked at it, (2) The building inspector signed and dated a statement on his letterhead saying that he looked at it and it was okay, or (3) The building inspector called you and told you that he looked at it and it was okay.