If I'm traveling in the opposite direction of a stopped school bus on a road with a median and there's a child that has walked across the median to get on the bus on the other side, do I still have to stop until the lights go out or can I proceed with caution once it's safe to do so?

I got lost while out of town and had to perform a U turn but didn't see the car coming up behind me and pulled out in front of them causing an accident. It was in a 50 km/h zone, clear visibility in both directions and I was stopped on the shoulder prior to starting the turn. It's pretty cut and dry...