Chesty, as I have speculated, the Windshear Escape was foremost in the flying pilot's mind, and he simply fire walled the thrust without thinking, which is a typical fatigue related rule-based error.
The application of beyond rated thrust in a very light aircraft was clearly the initiation of the sequence leading to the loss of control and a rational explanation for it I suspect will not be forthcoming.
This may simply have gone around because the speed was impossible to control, and the chances of a successful approach were low.