Thank you so much everyone for the replies and the help.
On the website from that greenhouse I was able to find a picture of said orchid with the label (roughly translated) 'Here in our "Cattleyahouse" is not only the perfect atmosphere for Cattleyas but also Laelias and Dendrobium have their own space'. So it really looks like that it could be a Dendrobium. But I guess to find out which species exactly I'd have to go there again