First you said they couldn't figure out the right dimension is 12m without hacking into CALT to get blueprint. That's why Chinese authorities could challenge them.And why didn't Chinese authorities challenge them by saying "there is no way in hell the LM-5 core stage contains a metal pipe with those dimensions"?
I said there's no fuel tank of that length. It matter becuase there're only two fuel tank in the core stage, a LOX tank around 7 m stacking on top of the LH2 tank around 20 m long. Only the LOX tank needs a long fuel pipe to feed the engine beneath the LH2 tank, which means the pipe has to be over 20 m in length.
So there's no way 12 m can be a right dimension. If you argue that the pipe could be broken, sure, then sewer pipe of any length could make the claim.
As for the second photo, frankly what the heck is that? It couldn't break a tree branch after falling from space? I've seen debris that break roof and wall of house.