He didn't look happy at all at being subbed.
More likely: Saracens are not in the Premiership so not bound by the agreement to release players, and are struggling mightily to stay in contention for promotion (a hoot of a story in itself). Thus, all hands on deck.
Normally I'd have Maitland in the XV and see this as a big loss, but in this match France will go all out to win by 20 scoring loads of tries, so the game should be very open - Graham/McMerwe/Hogg is a perfect back-3 for that. Or McLean