My dog was leashed when another attacked and a man interviened and got bitten help?

i was walking to my local park and as soon as i stepped foot 3 dogs surrounded mine and one attacked but my dog a SBT got hold of the other dog before it ad chance to bite him and as i lifted his lead high to prevent him being ground level were he could attack the other dog lunged and bit my dogs leg, when the man intervined he was bitten quite badly by my dog. when this happened i was apologetic and he acknowladged he was at fault, but i recently seen the man and he was being aggressive telling me hes taking me to court and i just want to make sure im ok i live in manchester england thanks.