Experience in Pushing Hands

I was pushing hands with my taiji brother today. I always felt that this taiji brother was strong, he normally did not use it, but when he did, I had a lot of trouble dealing with it. Today, he was trying to put his front leg between my legs to do a throw. I felt a strong sweep from his leg to my front leg. I held my structure fairly upright, then he fell forward two metres away. He tried a second time with the same move, this time he fell forward since I twisted him but in the opposite direction.  I didn't know what I really did, it happened fairly quickly. Both times I was able to remain standing in the same place.  I realized for things like this to happen, he needed to be committed for his move, and used a lot of power while I spent a lot of effort maintaining my structure. Because of that, a lot of potential energy was created like pulling a bow back, and the fall was triggered by the release.