I would not say I am surprised because lately Wolverhampton has been in fantastic form and this is just the result of how solid they are. I watched them against Liverpool and I believe they actually out played Liverpool in the counter and especially in the first half but they drop their guard and Liverpool had the edge over them.
Today game against Manchester city I think they were more prepared and the coach made great changes to see that the team carries their lead to the final whistle even those they let Manchester city equalize I still had a feeling they had what it takes to beat the citizens today. Now the league is open, arsenal and Liverpool can try to make this slip up count in their favor.