Even though Barcelona lost to Real Sociedad but they have really shown great performance since the season began which many didn't even know they will be this consistent. At least they are still topping the league with 6 points and even if Real Madrid win their outstanding game, Barcelona will still be topping with 3 points but they need to be more consistent now that the gap is closing a bit between them and Real Madrid. Because it will be disappointing if Barcelona allows Madrid to get to the top of the league, it will mean that all their efforts since the season started was just a waste. However, i trust Barcelona to win their next fixtures since they haven't lost two games consecutively.
Barcelona has seen a lot last season, even Laporta was convince Xavi will give him what he wants and there was heated arguments through out the season until he finally get Gansi Flick and I can't say for others, I am personally convinced with his performance since the season started, not all coaches get a chance to prove their worthiness in thier first year but they have finally stay at the top of the league, it will cost Real Madrid alot to be able to reach them.
Real Sociedad against Barcelona was a complete disappointment but it's better than Real Madrid that lost 4 games in a row. It was when they played against Osasuna they were able to change their game and Barcelona is still 6 points ahead and before then Flick would have find away to tighten their front. If not for Lewandowski goal was rule out by the referee, I'm sure we wouldn't be saying Barcelona lost but nothing can be done since the referee count it as null.