[The Newell]

After it overinflated did you dump the system and refill and what happened? Did it fill normally or did the same bag overfill again?
If this happened only once and has not happened again then I would say not to worry about it that this does happen as a fluke thing. I have seen it where one bag would not inflate but dump the system and on the next sequence everything worked fine. If it happens again then the control valve for that bag is either bad, or needs adjustment.