Couldn't Remake a Ranked game!?

One minute into the game my team and I realized Mundo was afk and decided we would remake. Everyone on our team spammed remake, but it said someone needed to be disconnected(meaning it thought no one was disconnected?) We told the other team, but still couldn't do anything about it. Mundo joined the game about 10 minutes or so in. There was no reason we shouldn't have been able to remake, is there? This is the match: http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/2308952573/226142399?tab=overview

and even if you look at the builds, Mundo's isn't recorded for some reason: http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/2308952573/226142399?tab=builds&participant=3

This lost me a promo game and I don't know if it was a bug or if there's a way to troll around remakes but, it happened. All Mundo said was about it was "fix my toaster"... Thanks for your time, and please do something about this Rito.