Phoenix

Corrected entry: When Harry and Lupin are practising the Patronus charm alone, the second time Lupin closes the boggart back into the chest he neglects to lock it in.

Phoenix

Correction: It is opened and locked by magic, as is shown in the close-ups of it opening. After Lupin closes the trunk the second time he leans on it, hits the top of it with his hand, and has a few more moments on and near the trunk while the camera is focused on Harry sitting on the steps. It would have been very easy, during this time, for Lupin to have magically locked the trunk.

wolfchild