"it must be due to human error, this sort of thing has cropped up before and it has always been due to human error"
i did a speed run the first time i played through that gaem and beat the elite 4 with an infernape at lvl 50, everyone else in the 10-30 range, and without using dialga. just get one strong guy and 50 or so revives. if your main guy faints throw one of the other 5 dummies in there, use a revive on your main guy, and send him back out when the dummy faints(always works for me). if even this fails then it must be the problem i listed above:P