Well, if proper maintenance was done and the part still failed due to a design or quality issue that was improperly QC’d (missed, skipped, etc) then yeah it could be Boeings fault.

They’re getting extra scrutiny right now because of all the incidents recently, and all the anecdotal stories of former employees talking about how a bunch of suits are destroying it from the inside to make a quick buck.

And frankly, they fucking deserve it.