I'd hope that it would be caught fairly early on - given that the AoA sensor is (or can be) a pretty important piece of kit in the software decision-making process, I'd have thought that they'd have "failed" instruments on the test rig - one by one and then in every possible combination, to see how the control logic adapted. Again, if the system didn't pick up that the AoA sensor was U/S and adapt it's behaviour to compensate then that could be a potential deal-wrecker... But I'd have thought fairly unlikely nonetheless.