..It says that when the engine was started the motor failed to disengage...which placed undue thrust on the main shaft....which defeated the pre-load on the main bearing..
ORIGINAL: Gaspar
..Supposing that the engine can arrive to idle with the starter engaged....that is a lot of supposition... Let me know what starter you use that can survive 4 minutes at 150Krpm. And the ecu should have survived 4 minutes at 50V of back EMF... that's reliability! Not many appliances allow a voltage 7 times higher than nominal...
And the suposition that a starter shaft (a fault outside the engine, again [&o] ) with his tiny 2mm of diameter can upset the preload and damage the bearings is ridiculous, sorry. No way that it can hold full 4 minutes and do enough force to upset the preload... and this force should be against the engine, just inversely as the sense of the bendix...