Be careful how you explain the delay and the reasoning why you stayed in ZAG and didn't take the (delayed) flight to MUC on 12-Apr.
I write this, as based on flight data you would have had a good chance to catch LH424 on 12-Apr. LH1727 arrived at 15.51 (scheduled 14.30) and LH424 left at 16.50 (scheduled 16.05). An hour would have been enough to catch a connecting flight in MUC.