Awww!!! Poor Dexter baby! Sounds like he got a night fright.

Sometimes birds will see something in the dark that will scare the daylights out of them. It has happened to Popcorn and Muffin several times too, and they refuse to go back into their cage until I comfort them for like an hour. Normally, its a shadow or something that frightens them. Do you cover their cage at night? That can, and does help reduce night frights.

I'll be praying Dexter's wing heals soon. The exact same thing happened to Popcorn before, and his wing healed completely after two days. He was holding it out like that too. I'm sure Dexter will be just fine.