A girl ties up a cat and puts it in the corner. She's not paying attention and it escapes. When she looks in the corner she sees the ropes, and she sees that the cat is gone, and she says "逃げられた".
Is that （猫が）逃げられた = 逃げることが出来た, or is it （私は猫に）逃げられた?
EDIT: Just to clarify, the first one is meant to be the potential form, and the second one is meant to be the passive form.