Alex Weldon: If ko threats favor Black, I don't see any perfect moves for White, because a doesn't seem to work. The best I can come up with is this. threatens a ko for the corner at , so Black connects there, and connects the White group to safety outside, because and have a monkey jump relationship, and so can't be cut apart.
I don't see any way to connect out if White plays at a, but maybe I'm wrong? The problem with here is that if Black has better ko threats, he can play somewhere around to prevent connection, and then at starts a ko which Black takes first.