A sense of decency? I recall we had a SA 2nd row Botha I Think a few years ago who was getting on - had a serious injury and said he was going to retire so said we could annul the contract.
Sadly however you are correct we are stuck until his contract ends.
Heard from someone last year who knows Cats family that his near death experience affected him to the extent that he was unlikely to be able to play again. In that instance if it was me I like to think I would say I cannot do this I am not fit for purpose so to speak so give me a couple of months money and I will be off.
How can he turn up to training and think he has the respect of other players when he know he is not going to be involved in any meaningful way. In fact what is the point of him going to training.
I'd suggest that the fact he was on the bench this weekend means your information is either old or incorrect. He wouldn't be on the bench if what you've described is the reality of the situation.