Can someone tell me why the /remake system failed here?

This is not a rant thread I'm just honestly curious as to why the enemy team was not allowed to remake this game.

So here's the run down.

The game is question is here, replay is available: http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/2382501277/1?tab=overview

Basically the enemy team had a Shyvana that did not connect. She never left the base once and out top lane vlad had a free lane. We asked them why they just didn't remake the game when mid game started and the enemy team replied with "It wouldn't let us"

I don't really understand why they couldn't remake, this game met every condition for them to remake. They had an AFK who did not connect. The game was clearly one sided and no one gave first blood during the /remake window.

So I'm just curious as to why the system failed here.