I forgot this was on our site....
Info supplied by Hominid
The attachment shows a representation of the "pressure bump" and, below that, what the "cabin climb rate" guage indications could be if the pressure pulse were long in relation to the leakage time of the guage. The curve is the indication over the time frame of the pressure pulse, and the circles show what the guage indication would look like at different points in time.
The positive and negative indications of the guage could have been larger or smaller than shown. They could even have banged up against the max limits on the right side of the guage. The whole sequence could have occurred very quickly, in which case it would seem that the needle jumped down instantly then back up instantly, then back to zero. If it occurred more slowly, this would seem more like a typical (albeit 1-cycle) "oscillation."
The response to the pressure bump could easily have been "the oscillation" except for the bump or ear popping not being mentioned along with the oscillations in the logged communications, or the later timing of the bump not corresponding to the logged time of the "oscillations," or nobody ever saying they were the same thing.