Forgive me if i am mistaken, or seem to be off at a tangent, and I accept I might be confused here, but as I understand it there were 2 locations where female staff could, and did, get changed.
The locker room, which was an unofficial location which had habitually been used (by virtue of its convenience) by a significant number of female staff to get changed, including SP, and where the incidents occurred.
Then there was also the basement female Changing Room (which I infer from what I have read was not as frequently or habitually used simply by reason of locational convenience), but which was, in fact, the officially designated location for female staff to change.
If my assumption is correct, and DU was given permission to use the female changing room specifically (and I think that has been indicated in the evidence given), then surely that permission only applied to the official changing location in the basement, and would not stand as any form of defacto indirect permission to use the unofficial space in the locker room.
In which case it would seem clear to me that DU, by choosing to use the locker room, was determined to use whichever facility gave him the greatest opportunity to force his male presence and his beliefs on the maximum number of women possible, and give himself the maximum opportunity to engineer a confrontation or a grievance.
Forgive me if I am talking nonsense but it just struck me as being peculiar and wanted to understand that aspect a bit better.