Wait a second--I hope this isn't true, because this is exactly what happened with the Genesis probe. It returned to earth and the drogue was supposed to come out after it had decelerated to a certain speed, but the accelerometers were mounted upside down so the deceleration was interpreted as acceleration and the drogue never came out and the probe cratered in the desert.
We can't necessarily be too smug about this. I seem to remember an American Mars probe that sailed right past that planet because someone put a period instead of a comma in a line of FORTRAN code. I have had friends that worked on the Saturn 5 that left because of the tension of building systems that could never be completely tested prior to a launch. We may be better off today with a combination of more experience and better test equipment, but we are also building more complex systems.
I'm not sure I'd put a lot of stock in an unidentified source and the Interfax news agency. I mean -- these are rocket scientists we're talking about, and they know how to install sensors. In any case, how would they know at this point?
Huge failure is right. One would think that there would be several tests and confirmations in place before actual launch. That's a huge loss of resources based on something that should have been easily caught.
The use of keyed connectors that can only be assembled one way is a good precaution to prevent reversed connections. Of course, if the connector is wired backwards that won't help. The second essential step is to gather baseline data and confirm that the device is operating properly. If indeed the sensor was installed upside-down, it should have been reported inverted data when standing on the launchpad. Exhaustive testing certainly proves its worth if it can catch a tiny error before it causes a huge failure.