My first thought was yes... Street Fighting is a form of CC and any MMC rolling an original 2 in CC earns Leader Creation.
Then I looked up A18.12 which confirms the wording... "anyime a MMC attacking in CC rolls an Original 2 DR..." The only complicating factor is A18.12 is headed up "CCPh"... is that intending to limit Leader Creation to CC performed in the CC Phase. I can't answer that one. Unless someone can point to an answer, I'd suggest asking Perry at MMP to make a ruling.
I'd argue that Leader Creation would be allowed as a part of Reaction Fire; it is not listed as an exception in D7.213. CC Reaction Fire (and, by extension, Street Fighting) is merely a form of CC which happens during the MPh and is goverened by normal CC vs. AFV rules as per D7.21.