If you fill the bearing and its sealed housing completely, where is the grease that has to be moved to allow rotation going to go?
An over-packed bearing will fail in one of two ways. Either pressure caused by the churning effect will cause the seal system to fail resulting ultimately in severe *under* lubrication, or the churning will cause temperature degradation of the grease.
I've seen both happen many times in industrial situations.
The general rule of thumb is to fill the bearing, but only pack the sealed area of the housing to 50% full.
Perhaps it was over-packed :-)
I've certainly ran cars for 100K and never replaced a wheel bearing. OTOH I've had one go noisy at half that milage. A failure at 11K means something was wrong for sure!
Chris