Able to schedule conflicting events

I have set up weekly restrictions for YMYW activities, and have encouraged leaders to update those restrictions, by creating an event detailing the activities. Of course, they almost never do this, so the restriction stays in place.
Today, someone in the Primary scheduled a pinewood derby on the 'Primary Calendar', and it conflicts with a YMYW activity .. both using the Cultural Hall. She should have received an error message when she submitted the event, since it clearly conflicts with the restriction using the Cultural Hall. Both events have the Cultural Hall selected, and now both are scheduled at the same time.

That's not how restrictions work. All you can do is restrict the use to a specific unit. You can't restrict it to a specific activity or calendar.

Since the scheduled event was done by the ward the restriction was made for, the system is working as designed. A message is generated only when another unit attempts to schedule an event.

Since the Primary created an event and the YM/YW failed to, many stakes would say that the location goes to the Primary. Restrictions don't count.