Apply change: Error when switching 2 items in array

[bcaudan]

I have this object:

{
    "id": "Release",
    "phases": [{
        "id": "Phase1",
        "tasks": [
          {"id": "Task1"}, 
          {"id": "Task2"}
        ]
    }, {
        "id": "Phase2",
        "tasks": [
          {"id": "Task3"}
        ]
    }]
}

When I try to apply the switch of 'Phase1' and 'Phase2' in 'phases', an error is thrown in 'applyArrayChange'.

I made a plunker of it: http://plnkr.co/edit/2eu6EeujOZOwxp0jewpl?p=preview

[paulpflug]

sorry for this mess ;)