How can I fix this iPad stuck in the language setup screen?
I figured out the answer. This state is called Voiceover, its an accessibility feature for the visially impaired, 

However when used unintentionally by someone who doesnt know the special controls of the Voiceover feature, it can seem that the device simply is not responding to touch. 

One simply has to tap buttons to select them then doubletap to click them, navigate to the Voiceover memu under accessibility and turn it off. Alternatively clicking the home-button 3 times in rapid succession enables/disables this feature.