It didn't look like he posted enough of the timing table to see the commanded timing at 3600/ .60 cyl. I have seen that knock at 3600, well below peak VE, can lean towards more false knock the actual. Without know how much timing is being commanded its tough to predict. You could as a check throw 15 degrees of timing in the cells and see what happens. If you have headers and exhaust, check to make sure that nothing is rattling around that could cause false knock.
Joe, you posted something that caught my eye! When in SD the pcm ONLY uses the low-octane table for timing???? Makes sense since SD is a backup to the MAF system and the PCM thinks the car is in trouble. Is this correct?
Howard