You can pick at the phrasing I used, perhaps I should have worded it more carefully. All I was intending to say is that he was the manager when they won the Champions League. So to answer you, no I don't think he was responsible for it happening at all.
I still think my point stands. There are examples of managers achieving tangible success and then being fired, which was the point I was making in response to the idea that we couldn't have sacked Wenger after he managed our team when we finished second.