Self topping plant just happened earlier than you'd of wanted. Happens every once and a blue moon. Search plant tops itself also got another main step outta it so it made up for the anomaly.. good luck with everything.
Also what were the ties for bc that could have something to add to the way things happened. If your plant was tied and cut early it would try to grow around the problem causing the anomaly maybe cut off nutes to the main and split up 3 ways bc you ties her to tight cutting into the main cola. All speculation from here but that's no doubt a topping inncident either from you or by nature.
I have one that did the same growing right now. This is from seed. It just decided to grow two tops. It's not that uncommon. I've had it happen before. I've had them split into three tops on their own as well.
On the first photo it looks like a third top, but it was the main stem that never continued its development. It grew the fan leaves but they remained together on their base, thats what im holding on the first pic.