Clicking a checkbox with ng-click does not update the model

How about changing

<input type="checkbox" ng-click='onCompleteTodo(todo)' ng-model="todo.done">

to

<input type="checkbox" ng-change="onCompleteTodo(todo)" ng-model="todo.done">

From docs:

Evaluate given expression when user changes the input. The expression is not evaluated when the value change is coming from the model.

Note, this directive requires ngModel to be present.