Champions League Bug?

Can someone please tell me if this is a bug? Clearly my GD is better than Besiktas. So howcome they go through and I don't?

In the Champions League, the groups are sorted on results against each other (like an aggregate score) before goal difference comes into play. Judging by that, you're 1-2 defeat at home against them has cost you. What was the score in the away game?