I'll ask the obvious question of why he was so intent on an overshoot at his prmimary alternate when he was established on a published segment of the approach. Iy makes it seem from the post that as soon as he was told the vis was below his mins, he decided that he was going to have to overshoot. Surely not the case I hope. Regardless if the vis was called below his mins, who cares, he's on a published segment of the approach, he should still be able to continue to DA and and if having the required viz, and being in a safe position to land, land at his primary alternate.