There were some thoughts, too, that some of the problems PT had with the new Red E1 provided by Mapdec were a result of improperly bled brakes, DOT fluid under the hoods, etc., because a lot of the complaints are consistent with what happens when you have a reservoir leak or don't use alcohol to clean up your DOT after a spill. That said, I doubt facing the BB would void the warranty. In the US, Specialized would have to prove that the facing led to the specific failure in question for the warranty not to apply. Specialized would likely not fight a customer over that for the cost of a warranty frame.
A lot of assumptions about specialized warranty there. Not sure I agree, but I get what you're saying.
The way I see it:
Got it built by a non-specialized certified/approved mechanic.
The mechanic purposely went against the manual instructions which explicitly state the works done will void warranty instead of sending it back to specialized for remedy.
I think specialized are well within their rights to point the finger at the mechanic if anything goes wrong.
And then it comes down to whether mechanic wants to fight specialized in court or not. I know I wouldn't be super keen on fighting specialized in a circumstance like that.
Then it comes down to whether the customer wants to fight the mechanic in court or not.
And the whole time the customer is without a bike in that process.
And all of that just makes me think... Read the manual and follow the instructions like a normal person. If there is an issue with a frame at sworks level, get the manufacturer to remedy it so you're covered.
But in this case there is a fool trusting a fool.