A couple of things I noticed:
1) You had NIS in your initial spray mix. Why? Carfentrazone usually does its job well enough without adjuvants. Unless you're targeting weeds with thick waxy cuticles or you're partnering it with a product that requires an adjuvant, the NIS really isn't needed. Just adding the NIS is probably what magnified the injury you saw on the P. rye.
2) What was your carfentrazone application rate?
3) Carfentrazone is a PPO inhibiting herbicide, so it has contact activity and doesn't really translocate. It works, in part, by dessicating cells and interefering with cell membrane stability. It is not really affected by growth stage or cellular activity.
4) Check the ai rates when comparing different products. At the highest label rates for cool season grasses, SquareOne applies 33% less carfentrazone than Quicksilver.
Just some thoughts ....