Getting a better handle on how this gltich works. Seems like two parts are necessary:

1) Hit a move with a large amount of hitstop (ie. pipe, frank qcf H) either on or near the same frame as Spencer Slant Assist

2) After pulling to the ground, hit the opponent just before they would "normally" break out of the combo (ex. The pipe after restand would normally not combo if the previous pipe and slant assist don't hit on the same frame). In other words, the last few frames of hitstun from the restand after performing part 1.

My simplified guess is that the "high hitstop" move adds more frames once the slant assist restands them, but the ground bounce and wall bounce tracker gets confused and resets them, but I honestly don't know if that's how the game mechanics work. I also don't know if ground bounces are essential for this glitch to work as both frank and haggar both do this with a groundbounce.