I accidently pressed R2 and sent an shout to the Guy sitting at the entrance in mzulft. Now nothing happens. Is there an solution for this?
If You can, reload the Autosave that was made when entering Mzulft.
Try Looting the body? He normally has a bit of dialogue, then He dies and Our character has to loot the key and expedition journal from the corpse.
You can't reload? You should have an autosave from entering, and one from right before your last fast travel or about 15 minutes of regular travel. Alternatively you'd have to go back to your last manual save.
So the guy just doesn't talk? Is there any interaction prompt when you get close to him? Can you pickpocket him? Is he dead?