You know, these things are great, but I have found that they do need many fasteners to hold in place, and if one is hit accidently it could be bent, bowed, or flattened out. This makes them very hard to straighten out and to take mud.
If its too bad, I would replace the entire outside corner with fresh. Mud it, and its new.
But, sometimes you can re fasten this bead at a bad place and mud it in and its fine also. Sometimes a controlled whack with a hammer will also persuade it to go back as planned.