I hesitate to say this, but I completely agree.
That said, I understand that he had an option in his favour any could have left at thee end of this year.
Given his injury concerns at the moment, I would have been surprised had he put himself on the open market.
Whilst he might be quality now (and that's an argument from another day, but leaving it aside for the moment) I just can't see the logic of signing a bloke who's just had a serious injury, and who may never be the same player again (note Tallis' example) in circumstances where we are almost now certain to lose a back rower who might be one of the best players in the game in two years time.
Seems a very shortsighted decision to me.
PS if this doesn't cost us Sua, then it will definitely cost us one of Haas, or Fafita... Just a question of available money and available spots.