Honestly that strike is distracting from what was overall a really fantastic midfield performance. He was there in defense when he needed to be and made some excellent tackles, and made his forward runs late instead of early so he could be a passing option during our buildup play.
It helps that Galatasaray are absolutely shit, and barely even move in midfield, but he looked like a real CM yesterday, and that kind of play will work against the top teams as well.
Dules saying he relies on physicality but when he's not 100% the rest of his game crumbles, but I think it's all in his head. His last protracted "dud" mode was due to Wenger expecting too much of him, primarily by denying him a clear role in the team that suited his strengths as a player. Hopefully this more recent run of bad form is over, but I'd say the reason why its happened in the first place is that Wenger has once again failed to define his (and other's) role in the team.
Playing in a 4231 obviously really helped him, he knew what to do and how to play it, what his role was.