Yes the pipe not fitting in the opposite hole is strange isn't it, but I think I have an explanation.
Replacement parts callipers must be drilled with the correct size hole on both sides - thus only one skew for replacement callipers (saves stocking two types) but factory fitted ones were probably only drilled with the correct size hole on one side!! (Maybe to save a few seconds during manufacturing by avoiding precision drilling an extra hole that didn't need to be precise on the bleed nipple side)
Another example of this sort of practice is that factory fitted Hydractive ECU's were always different part numbers for Xantia and XM, but the later replacement parts ECU's were one size fits all with a one time programming with a Lexia to tell it it was for a Xantia or XM before installation.
It makes sense to reduce skews for replacement parts that are going to sit in stock for years, even if the unit price is slightly higher, but possibly not for factory fitted parts where they know exactly how many of each type they need to make the cars they plan to produce, in which case they can cut corners like not precisely drilling a hole that they don't need to...
