Jonker JS-3 in Sagebrush

"After 16 years flying the ASW-27, muscle memory was involved. On downwind, the dive brakes were used to adjust appropriate pattern altitude starting from a high pattern entry from overhead, then somewhere on downwind the brakes were lastly put away. But, apparently not put away properly. The JS3 has several detent stops for holding the dive brake open at partial positions whereas the ASW-27 has only one detent at the closed and locked position. "

My question is why was there need to put the dive brakes away in the first place? From my understanding and initial training, the ideal way to fly a pattern is with the dive brakes halfway deployed. Obviously, there will be adjustments to the dive brakes to account for lift, sink, wind.... but at least partial dive brakes should be used throughout the pattern as to make the glide angle in the pattern steep enough to account for the previously mentioned factors. If this is the case then why was there need to put away the brakes on downwind? Is this differences in training, lack of foresight, or just habit?

Not trying to critique the pilot just trying to understand the scenario so I can avoid doing a similar thing.