Why do you say that? It seems clear to me it is. Do you disagree that A being caused by B usually means A and B correlated[0]? That's all that's necessary to say correlation is evidence for causation.

0: I know there are some exceptions, but they seem rare. http://stats.stackexchange.com/questions/26300/does-causatio...

evidence != proof

He is simply stating that correlation can indicate a need to look deeper into the data, which is IMO true.

Yes it is. If A and B are correlated, and C and D are not correlated, then absent other information, it's much more likely that A and B are causally related.

I think people get confused because there can be evidence for things that aren't true.