On special Lagrangian fibrations in generic twistor families of K3 surfaces

7 pages. Final version based on the referee report. To appear in Annales scientifiques de l'\'Ecole normale sup\'erieure as an appendix to Simion Filip's paper arXiv:1612.08684International audienceFilip showed that there are constants $C>0$ and $\delta>0$ such that the number of special Lagrangian fibrations of volume $\leq V$ in a generic twistor family of K3 surfaces is $C\cdot V^{20}+O(V^{20-\delta})$. In this note, we show that $\delta$ can be taken to be any number $0<\delta<\frac{4}{697633}$