Branches drying up

Wow, that branch is completely necrotic. Things that *could case a branch to tamp off like that. *Damage *Infection *Fungus I really can't see more, but only a vascular disease would cause something like this outside of damage to the branch itself. From the pictures, I'm leaning towards unseen branch damage, perhaps it broke while moving it and you didn't notice? The entire branch and the buds attached to it look dried and bleached, the bleaching would come from the lights once the tissue has died.