Whilst incredibly disappointing for ESA, this is unfortunately not their first IMU-failure rodeo.

An Ariane 5 launch back in 1996 [0] suffered a catstrophic failure after the inertial reference units gave bad data, and the flight control computer accepted it as gospel.

It is sad that they might have lost another platform due to a lack of appropriate range / saturation checking, especially as there was a radar altimeter onboard telling them they weren't underground.

[0] https://en.wikipedia.org/wiki/Cluster_(spacecraft)#Launch_fa...