They're running with the theory of it being the teflon seals, but IIRC the problem is that it doesn't explain why the thrusters appeared to be operating relativ

They're running with the theory of it being the teflon seals, but IIRC the problem is that it doesn't explain why the thrusters appeared to be operating relatively normally in a test at the station. The seal deformation should be permanent, in which case the thrusters shouldn't have recovered on their own, meaning that they might not have caught the real issue. That's what's making the risk difficult to quantify.