My unit skipped back as you describe before 4.01. It seems to be at 1/4 frame rate but looks like more if you go by the timer which is counting the time of the delay from the live record point. Between that and the delay in the timer reappearing it might be giving the illusion of bigger skip back.
Perhaps it is, and I've just been doing so many different things with the 622 today
Both my receivers have always skipped back and forward several frames on the first press of skip fwd or rev after pause is pressed, but then on the second, and subsequent presses, both fwd and rev moved 1/4 frame with each press.
I have a some baseball games from last season, and am able to go back to specific plays I remember, when I was able to move a thrown ball in-and-out of the glove catching it, frame-by-frame, moving it about 4" with each press....forward or back. I returned to those same plays. On forward, it's still the same, 4"/each press....on reverse, it skips back to before the ball was thrown.
I'm fairly certain the increment back, was the same as the increment forward prior to 4.01, and I'm very certain I could toggle movements (seesaw-like) back-and-forth...baseballs in-and-out of gloves, basketballs in-and-out of rims, etc.
I'll rest these old eyes, and take another look at it tomorrow.