The majority of the failed thrusters were on the service module which was discarded before re-entry and burns up, meaning none could be recovered.
The command module thrusters are only used after the service module has been discarded in order to align and control the capsule during re-entry.
There are 12 of these thrusters which were tested prior to re-entry and one failed. That’s not a major problem, they are used in pairs and the remaining 10 were more than adequate for re-entry.
But it does mean they have one failed thruster available for strip down and examination, which should allow them to confirm the failure mode which, so far, has been based on ground tests and simulations.