I was considering why Leader is preventing the referees from watching the StL match. I think it's to force the specific condition of StL being collection of the loser's life. The last time StL happened, for some reason or another, Leader spared Baku. I think to prevent that sort of emotion from taking over, Leader is making it so one of them has to come out of the match dead, so that the rest of Kakerou can properly accept it. This more holds true for Baku winning than Leader winning though, since I was like 90% sure that Baku would spare Leader if he wins StL, because that fits with his ideology as we know it.
Although, that would mean the rest of Kakerou doesn't trust the presiding referee, which I doubt would be the case.