In the attached repro mission I've given an AI unit and the player both identical waypoints at different positions. Both waypoints have a completion radius of 50m and the player can safely observe the AI unit using the zeus interface. When the waypoint is completed a high explosive shell will be dropped near the unit, this can be used as an indicator for when it is considered completed. Step by step:
1. Launch the attached repro mission.
2. Enter the zeus interface and observe the pre-placed AI unit.
3. Notice nothing happens until he reaches the center of his waypoint.
4. Exit the zeus interface and head toward your own waypoint.
5. Notice that the waypoint event is triggered when you get within 50m of it.