Asset Bundle Unload

Say I have the following bit of code:

public IEnumerator LoadResources()
    WWW download = new WWW("some_asset_bundle");

    yield return download;

    GameObject go = (GameObject) download.assetBundle.Load("myGameObject", typeof(GameObject));

    // ... some other code here...

If 'myGameObject' was the only object in the asset bundle and I would manually destroy the object returned via the load method using GameObject.DestroyImmediate(...). Would this be equivalent to calling download.assetBundle.UnloadAll(true)? Or does the asset bundle still hold onto data that was loaded into memory until UnloadAll(...) is explicitly called?

There is memory that can only be unloaded by calling AssetBundle.UnloadAll. So if you are not using anything in the asset bundle anymore, you should definately call that function.