well, I don't know if it'll fix the problem, but replacing the victory/
animation is simple.
Open up the FitCaptain00.pcs for Goku, open up the tabs for ModelData[0] and you should see a gray icon for FitCaptain00. Right click, "preview", scroll down to zoom out. On the right tab of the model viewer, there should be a "load" button. Click, find the FitCaptainMotionEtc.pac for Goku, and open it. All of his animations are now listed on the right tab; scroll towards the bottom of the list and you should find the victory taunt and losing pose, which you can click on and preview by hitting "play" on the bottom tab.
Open up another Brawlbox, and open a FitCaptain0X.pcs (doesn't matter if it's Goku or not) and load the
original FitMotionEtc for Captain Falcon. If you don't have it, go to the resources page in Brawlvault, find the ISO and go through the folders (fighter/captain) and you should find the original file.
Anyways, once you load the original MotionEtc, find those same animations from earlier by scrolling through the list. Right click, "export", and save it somewhere temporarily. Do this for every animation you want to revert to the original.
Now, go back to the model viewer for
Goku's motionetc, right click on the animation name, "replace", and load the exported files (captain falcon's original animations) in place of Goku's. Finally, you can save, close the model viewer, and "save as" the MotionEtc.pac. And you're done.
Feel free to ask any questions if this is still too confusing.