@kiang I just checked Zootierliste again and see the Asiatic at listed, so I think you are right. I see there are other photos labelled as such in the gallery
As far as I know Madrid zoo doesn't have American black bears. They have a bear exhibit with Asiatic blacks at one side and Sun bear at other side, Brown bears in the European section, and giant pandas. In the past they also held Spectacled.
@Kakapo I've just noticed that their website says they do have American and Asiatic black bear ... would they have them in the same enclosure? The brown bear I posted today was in with this one (you can see it in the top right of the photo.
Now I see that Zootierliste includes American black bear for Madrid zoo. It's strange for me, as I've visited this zoo in june 2017 and I don't remember any American black bear in the zoo nor in the list that I've made with Zootierliste previous to my visit. But clearly ZTL says that is here since 2011 and seen at 2016, so... you must be right for sure.
Anyway the bear in your photo looks like 100% Asiatic and extremely unlikely to be American to me, judging only by the appareance.