Mate what part of it aren't you getting... it was enough to knock him off balance(nudge push... call it whatever you want it doesn't change a thing), without it he doesn't stumble... the amount of force is irrelevant, for the last time it was the use of hand or arm in the back that caused him to stumble, you cannot do that unless the rules I posted earlier have changed?(at least I looked for the definition, it was off wiki because I struggled to find it on the FA's website to be fair, it's no wonder our refs get off the hook they don't want us knowing them by the looks of it)
Yes I agree we should have just chalked it off and carried on but we seemed to turn gungho and gave the game away.