Hi,

So on angular-google-maps 2.0.16 .. 2.1.0 (haven't tried any previous version) the circle events are not triggered and the changes in center / radius are not reflected on the model. After a short walk through the code the problem is with scope.events on the circle, if it is not set then the listeners event are not set.

The quick fix is to define events (event it points to an empty object) and the changes will be reflected on the model. This bug might be related to #1271