IMO.. Breaking paddles is not always about brands or how strong you are.
These carbon shafts need to be looked after and checked every now and then for anything like this.. (see pics)
This fracture looks obvious in these pics but it took a few attempts to show it because in different light and the way carbon reflects they are often very hard to see.
They are often caused by dropping or banging them while out of the water or against the board during a fall in the water.
Sam from Kialoa was telling me once that Mel Pu'u still has his original Shaka Pu'u from years ago and uses it all the time..and you don't get much stronger than him.
DJ