> I believe you're over-estimating their intelligence.
One of my favourite orca stories is the killers of Eden[0]. The wiki page is short and worth a read, but to summarize: a pod of whales learns to herd whales into a bay and alert humans to them. Humans harpoon them and the pod helps drag them back by pulling on the ropes. The carcass is left overnight for the pod, that eats its lips and tongue. Afterwards, the humans haul it back.
Why would the orcas alert the humans unless they realized that the humans were responsible for the harpooning? Furthermore, just the act of slapping the river with water to attract attention is already quite advanced. And why did they only eat part of the whale (and always the same part)? Why did they never eat the humans?
[0] https://en.wikipedia.org/wiki/Killer_whales_of_Eden,_New_Sou...