I expected Real Madrid could lose points to Betis, as Betis is doing fairly well this season and both of those teams tend to perform much better at home, but I thought the most they could hope for was a draw, but they bagged 3 points.
It seemed like Real Madrid might have become too confident or too relaxed after scoring an early lead and got punished for that. They now dropped to the 3rd place as they got overtaken by Atletico with 2 points gap between them.
It most likely was just a one-time flop, as yesterday Real proved their superiority over Atletico by beating them 2-1 in the Champions League.
I don't think it's a one-time thing though. Madrid has been really inconsistent this season and a lot of times they've been bailed by the individual quality in their squad. Madrid has so much quality that any player can produce a moment of magic at any time and that is what happened against Atleti.
Days when the individual quality doesn't impress or when the opponent play better, they suffer.
I don't think Madrid would be able to win the La liga because they will still drop more points in the league. I agree that the other 2 teams will drop points, but not as much as Madrid. The champions league and Copa del Rey are the only hope of Silverware for Madrid this season.