What is the right course of action here?

Your answer is correct because you chose to wait until the cyclist has completed the turn. According to German traffic rules, when a cyclist is turning across your path, you must give them priority and wait until they have safely completed the turn before you proceed. This protects vulnerable road users and prevents accidents.

You should not take priority in front of the cyclist, nor should you use the horn to warn them. Horn use should be reserved for emergency situations, and taking priority unlawfully is dangerous and against traffic regulations.

In short, always yield to cyclists crossing your path and wait patiently until they finish turning. This ensures safety and respects the rules for giving way.