Has bad luck or bad finishing been hardest on Arsenal?

I am sure that some Arsenal fans will be sick of hearing that the Gunners have been unlucky, but it is hard to get away from the fact sometimes and once again tonight against Barcelona in the Nou Camp a key moment went against Arsenal and it could have proved to be a turning point in the game and the two-legged tie in general.

The pundits after the game were talking about that possible penalty for Iwobi and, after replays showed that Mascherano had caught the young Gunner even if there was no intent, we should have had a spot kick and been playing against 10 men. Wenger had clearly not seen the evidence or he would have made more of it in his post match comments but he did say that he felt that Barca were wobbling a bit when Elneny did make it 1-1, so how much more would they have been feeling the nerves at 2-1 down and a man down?

Arsenal really have had some shocking luck with decisions at key moments this season and it must be said that this has really hurt us. At the same time, we still have ourselves to blame for the failure to finish so many chances since the turn of the year.

Even without the penalty tonight we had lots of chances to really get at Barca and did not take them, just like in our FA cup exit to Watford and our damaging defeat to Swansea in the Premier League recently, to name but a few of many games like this. With better finishing we may not have needed better luck and a non-penalty would be a side note. What do you think?