Well, we know that Orcas teach their young to hunt using waves, and by beaching themselves [0]. So it's not a stretch to assume that this is acquired knowledge, and not instinctual.
We also occasionally observe a particular orca pod hunting an unusual prey other pods don't hunt, using some novel technique we've never seen in orcas before.
I can't think of a particular example offhand, but that sort of thing sure looks like learned tribal knowledge.
[0]: http://www.nature.com/news/2007/071214/full/news.2007.380.ht...