I want to throw intuition into this insight. A gamble based on a 'deliberate' shortage of knowledge increases the intensity of non-gamble-domain-specific awareness of scraps of experiences that, if accumulated, fit the pattern one gambles on (process and outcome). Risk aversion can be an instant accumulation of intuitions about factors that lead to the success or failure of the gamble. An "I should have know but did it anyway" kind of thing or "if only I had thrown a little more cpu and time into this consideration". So whether it's rational or not is the result of 'mindfulness' in that specific domain, which leaves risk aversion itself as a kind of no-brainer for most people most of the times when they (don't) act on it. Excluding coin flips. What do coin flips have to do with the human kind of risk anyway? And the hunter in the story is emotional (love or desire to dominate) which already excludes rationality and his shortage of knowledge extends to the domain of long term partnership between humans with personality, responsibilities and expectations of him, the prospective partner and those of the tribe.