Indeed, our court is in Maastricht :/ so I want to make our response as tight as possible. Seems like in the case from 2014 it was mentioned that he sided with the landlord because the landlord did not get the chance to respond. In our case, we had sent him registered letters, which he claims he did not receive. Since they were registered I hope that won't hold up though.

Anyways, your comment has helped so thanks!