Apparently not a very prominent question. Takes months for someone to answer. Anyways, let me comment.
All the shame for austerity is coming from the rules that a single currence imposes. Countries who spend more than they earn can not simply print money to cover the debt. No self balancing by currency devaluation possible. Leaves only the labour market as corrective. If labour cost is too high, the corrective is to have less people work, thus raising unemployment rate. On the other hand highly competitive economies will hire people and drive their unemployment rate down. Question is: Is this related to give up sovereignty, to have a single currency, to have the Eurozone birth error of central money control but local governments? I don´t think so.
Certainly it is very sad that Spain has an unemployment rate of 20% plus while Germany´s is less than 6%. But that is not the fault of imposing a single currency. Explanation:
Take a deeper look into Germany with its 16 states. Bavaria (where the BMWs and Audis are made) has an unemployment rate of 3.something %. The state of Brandenburg (his majesty´s sandbox) features 12%. No excuse for any economic birth defects, same currency, same government.
Apparently it is not important who makes the rules (supposedly Germany), whether there is a lack of correctives (no currency devaluation possible) or if governments behave thrifty or not.
So - Germany miscalculated effects of austerity? No.