Some times it is easier to define something by what it is not. For instance, when we study theology, we are better able to say what God is not, than what He is. God is not selfish. God is not evil. God is not limited to space and time.
In the case of ecumenism, it is sometimes given the simple definition of working toward true Christian unity. This is well and good, but what does that look like on the ground? That is harder to say. But, what we can say is - this incident is most certainly NOT ecumenism.