To be able to make any useful comment, I'd need to know the details of the waypoint flight, where each waypoint was, your starting point and the recorded flight data from when the controller was in contact.Wind is what i think too, but the drone detects wind, so it should know to do a low battery rth. I've had missions when it did a low battery rth and came back with 40% battery. What other information do you need. Speed was 25mph. No hovering.
It still might be tricky is a lot of the route was out of contact.