Possible bug in SAOPass - outlines around objects


I’m having a stab at adding SAO to my scene. I looked at this example and it has a weird outline around the spheres:
Link: https://threejs.org/examples/webgl_postprocessing_sao.html

I’m looking at the SAO output pass and it looks like this (it does not look correct, it should only have AO between spheres not around them):

I found this example which is using the exact same scene/parameters (the SAO pass look correct):
Link: https://rawgit.com/Ludobaka/three.js/sao/examples/webgl_postprocessing_sao.html

It sure looks like a Z-buffer linearization issue, but I cant figure out how to correct it. I saw this post on stackoverflow which seems to be the same problem as I am seeing in three.js:

Have I run into a bug in recent version of three.js?