"How could the blunt end of a tap possibly cause damage to a crankshaft in the bottom of the pilot bearing hole? (Or a pointy ended one for that matter?)"
Good morning Carl.
The thread-the-bushing method works by bottoming a bolt threaded into the bushing in the hole in the crankshaft. Then when the bolt is turned, the force the bolt applies to the bottom of the hole in the crankshaft is the same force that forces the bushing out. In the unlikely event that he bushing fit is extremely tight the tap could start marring the crank and he might not want that to happen.
Do you understand, or is further explanation required?
