I had something similar happen a few weeks ago. Nexstar was taking off, it got squirly at the end and then some nice wind hit as it lifted off. It shot straight up in a vertical and was still climbing. At about 25 ft right wing dropped. I didn't panic and waited to see what it was going to do. I just let it fall like in a stall turn. When the nose dropped I gave it a little up elevator and it leveled off and pulled out of it. Granted, I was now going the wrong way but I learned from it!