Hi, nice to meet someone who also improves the trail maps around LA. I often use the USGS 3D Elevation Program layer, which often shows paths well, even when hidden by trees. This is in conjunction with Bing and Mapbox layers, and I think all of these qualify as aerial imagery. So no, not a mistake, and I've also hiked most of these trails as well. Let me know if that helps; my goal is to improve these maps as best as possible but if I err somewhere am happy to be corrected too.