Tbf, it sounds like neither side did a stellar job here.
Poland not reacting "for several hours" makes it sound almost deliberate.Then again, I wonder how German police "informed" Poland for there to be no reaction. Did they fax?If they think the situation requires an immediate reply, why not call them? Surely a dedicated border patrol unit would have a contact number.Also, despite Schengen I don't think police can just cross the border to another state unless in pursuit of some fleeing criminal.And just dumping these people in some random location without any involvement of local authorities doesn't seem like proper protocol.
It should be noted, that this doesn't allow the Chancellor to micromanage the Ministers.The Chancellor can set the political agenda and make high level decisions but Ministers have some degree of constitutionally ensured independence in how exactly they implement policies.