I don't know whether "called their bluff" is the right metaphor. But I think that Greece came to this conflict with one (possibly unspoken) threat to back their position: if the door was shut in their face, they would leave.

Not only would Grexit create considerable shockwaves on financial and currency markets, but the (likely) modified relations of Greece with Russia, at a time when Turkey also shows signs of increased entente with Russia and the abandonment of EU ambitions, while the Balkans are far from entirely stabilised and Ukraine...

Whatever Schäuble and his ministry wanted, Auntie Angela has this big problem of getting out of the Ukraine mess without it blowing up in her face. I think she may well be more concerned with that at the moment, than the defence of orthodoxy wrt Greece.