The fact that Swansea were allowed to start a counter attack when the scoreline was 1-0, shows that the team/Wenger have learned not one iota from the Anderlecht game. Gibbs' foul was necessary to stop it, and the FK was just brilliant, but the whole situation prior to it was yet another error by us.
The 2-1 was just a consequence of having a LB as CB. Kos wouldn't have lost an aerial duel with Gomis. I won't fault Monreal, he's doing his best.