GamePress
Caught a shiny Magikarp - and almost transferred it!
After shopping at a grocery store, where I caught about 5 Magikarp, I saw an unusually colored Magikarp in the parking lot... and caught him with one razz berry and ultra ball (CP 124, Lv 25, IV 58%). I suspected it might be a shiny (PG finally upgraded to 0.59.1), but just to be sure I thought I'd try the transfer trick (attempting to transfer a shiny to the professor is supposed to give you a warning) - but guess what, I didn't get it!
It just gave me the standard question - Are you sure you want to transfer Magikarp to the professor? - and if I hadn't paid attention, I might have transferred this beauty!!! I almost fainted (well, not literally).
So be warned - don't expect a warning!!!