Ron, once again, you provide concise, pointed evidence of the anomaly. I wish my customers were that adept at relating failure modes.
Anyway, one your first red graph, there is also a little wobble, right at about 6.5 seconds. I wonder if that is the same thing, just not as pronounced as the "bog" phenomenon? As small as it is, it may go un-noticed.
I wonder what the difference in the time/G-force increments in the graphs could tell us? Is there a way to get the G-Force to make graphs having the same scale of units? The second graph covers a shorter time period, which is almost like a "zoom", magnifying the uh, uhm, waveform, so that smaller perturbations appear more pronounced.
Regardless, it is still clear that something is happening there, regardless of differences in graph scale.
Hope I don't sound pedantic.