That's not really the point is it, suppose the loop was entered into at 500ft instead, do you really think it is prudent to exit the loop at 300ft above the A27?
I think it's more complicated than that though. There is more than a suggestion that once the aircraft was obviously too low an attempt to pull up hard caused a stall and a loss of more height.
It could be that he was originally flying so as to exit the loop at the same height he entered it, but lost the extra few hundred feet at this point.