Looks as though it thinks you were making constant upstream requests so were able to skip the queue by piggybacking requests for the next grant onto the previous data transmission, bringing down your minimum latency.
Could also be a test of something involving a lower MAP interval.
Given your lower minimum latency, the notably higher average and the maximum while this person has a 'normal' minimum, small average increase and is plagued by spikes rather than constantly increased latency it doesn't look like the same thing.