I think this will not be their last mistake, but the main thing is not to make them too often so as not to let Real pull too far ahead. I also thought that Barcelona should easily beat such an opponent, no matter that it was an away match. And after Rayo Vallecano equalized, Barcelona still had enough time to score again, but they failed to do so. From Barcelona’s attack, I expected a better performance, I can’t even remember the last time they scored fewer than two goals in a match.
Flick is doing a good job, in the end he's not far from the top and we're just at the beginning, there's no point in worrying at this stage of the championship, i am sure he'll make his mark.
On the other hand, i am worried about Atletico Madrid, only 2 points seems like a clear sign of crisis.