The fact they had carefully prepared wooden spears shows they actively hunted game. Having stone tools merely means they cut meat up before eating it.
One of the strong thesis is that early man didn't hunt. Rather, relying on his smarts he let other animals, e.g. lions, tigers, bears, wolves ~ kill game which he then stole and ate himself!
Probably both hunting and opportunistic scavenging took place. Even chimps have been observed in the wild cooperatively hunting. I'm sure early man has been using sharp sticks since he learned to stand upright. As to when man learned to carve a sharp point on the end of a stick.......I'm guessing way earlier than 400,000 years ago.