Costas Lapavitsas was one of

Costas Lapavitsas was one of the Syriza MPs who left and who has always argued that the "solution" was to leave the euro and restore the drachma. He stood against Syriza  in the elections in September and wasn't re-lected. So there might be a bit of sour grapes there too. In any event, as you point out, leaving the euro wouldn't have meant that the government could have abandoned austerity.