Especially after the warnings before the flight attempt. He knew it was marginal.
I worry that he did not actually understand that it was marginal. He had not learned to be afraid of being in that regime of flight. Very occasionally, one has no choice but to be in that regime of flight, but most commonly, there is a choice. Being afraid of high AoA, behind the power curve just after takeoff should be instinct, not disregarded as being over cautious.