Look at the slow motion, I aim my gun and shoot, then "player used sync" appeared over your head after the bullet had already begin to be fired. I wasn't trying to damage you I shot you before you /synced its very bad timing but if you look at the video you can see
Yes, it seems to be truth. Still, as for me, it doesn't justify you completely, as you, being an experienced player, definitely knew that you'd kill Mia with one shot if she uses /sync, even if you were not intended to do so, and you knew that terrorists often /sync after map end to dance on president's dones or to hit his corpse.
So, considering the fact you probably haven't killed Mia intentionally and you apologized, I'd give you a warning if I was an admin, so next time if you anyhow get into troubles killing anyone after map end, you'd receive a moderate-term ban.
But, any decision from the real administrator? This case can't remain unsolved for good...