With the findings of truck problems with the S5 cars this reminds me of a problem NYC Transit had with their 745 car R46 fleet dating from the
second half of the 1970s that were built by Pullman-Standard which were cracks in trucks supplied by Rockwell International.
I recall a lawsuit by the MTA sought to have the R46 trucks repaired or replaced and in time this fleet is still in service on routes such as the A Train.
Not sure what the exact outcome was but the problem ended up being solved.
Can SEPTA invoke something similar against Rotem to either repair or replace defective trucks or their components?
They replaced every single truck and did a LOT of modifications to those cars, and they still sucked for a long time.
My guess is Rotem will honor the warranty, try to sue Columbus, get nothing out of them, and either chalk it up to a learning experience, or pull out of the US market altogether.
Of course, going with Kawasaki might not have helped in this case - it was probably SEPTA who wanted that truck design. I can't imagine Rotem willingly went to a small time manufacturer teetering on the brink, to build a 60's vintage design, when there's much better likely off the shelf available to them.