Is this even possible?
Answers
I suppose that with so many Magikarps spawning you can easily gather a shitload of them by spoofing. As you said, you've caught over 100 and I've caught loads as well. Imagine how many a really dedicated spoofer can catch.
And sooner or later he/she/the asshole will get a 100IV one. And they probably got loads of candy and dust as well, so even a low CP one will do.
Here we are, catching every orange, floppy bastard we see and can't get a single shiny one :(
Assuming the chance of finding a shiny Pokemon is the same as in the main series games (1/4096), and the chance of finding a perfect IV Pokemon also being 1/4096, the chance of getting that 100% IV Red Gyarados is 1/4096•4096 which is 1/16 777 216. One in 16 milloin! That's like winning the lottery! Although it is likely that the chance of finding a shiny is higher than in the main series games, it would still be unbelievably rare to find a perfect IV shiny. This leads me to believe that it was not aqcuired by spoofing and sniping 100 IV Magikarps as finding a shiny one among those would be as hard for the spoofer as it is for us legit players to find normal 100 IV pokemon (Assuming the chances for shinies and 100 IVs are same at 1/4096)