If the Daemon Codex shows us everything, FAQ's aren't always 'automatic'. Skimmers crash to the ground, rhino suspensions collapse, yada yada.
Also seems perfectly within the fluff to have a weapon that somehow controls gravity stop a vehicle in its tracks simply by making it much heavier than it was designed to be. Cover saves are taken against glances and pens, not against hits. Seems pretty obvious that by detailing the process in which you resolve Graviton hits against Vehicles (after hitting, roll a d6, 1-5 nothing happens, on a 6 the vehicle is immobilized and loses a hull point) that it is avoiding the entire issue of cover saves against glancing and penetrating hits. As it does not specifically mention disallowing cover saves vs vehicles I would not try and and claim it. It still removes hull points as a standard penetrating hit would, and vs infantry the gun allows saves as normal.
Big Blind Bill wrote: The issue is current a loophole at the moment, the quote you have stated does not resolve the issue as we need clarification as to whether the hit 'count as' a penetrating hit.
