That’s the whole thing Nat. The end user always blames the builder for what he screwed up. Even when it is built to his (end user) specs. Despite the machinists warnings and objections.
That is just fucked up , if i blow and engine because i miss a shift or forget to shift I don't blame the builder i fix it and cover the cost . if it is a build defect that is a different story , you can tell what happened once you open up the engine . it's no wonder shops are fed up and closing choose your customers carefuly .
And then try hard as hell to make the machinist repair it for free.