Lost my chance at a shiny Giratina in Platinum, thanks to my stupid thumb. I have an elastic holding down the L-R buttons, so I had my thumb near the Start-Select ones, for easy access. I glance down and see shiny Giratina too late and my thumb pressed down on reflex, SRing the game.
I'm totally upset about this, I could have had Giratina today and I could have started SRing for Darkrai tomorrow. Now I just gotta hope the RNG is nice to me and another shiny one appears. I'm hoping that its similar to if you got a shiny Starly at the beginning of the game when SRing for a starter, but I doubt that.