Assume that $\Sigma$ is a stricly convex surface in $\mathbb{E}^3$ homeomorphic to a sphere. Further, assume that $p_0,\ p_1\in \Sigma$ are intersection points with planes $z=0,\ z=1$ and the surface $\Sigma$ is between the two planes. Then $p_1$ is a cut point of $p_0$ ? (I do not know whether or not this is true)
Definition : Consider a intrinsic metric on $\Sigma$, a length of simple path. Then $p_1$ is not a cut point of $p_0$ if there is unique shortest path from $p_0$ to any point sufficiently close to $p_1$.