Confirmations:
a). Yellow S symbol
b). Pokemon is a different color from its normal coloration
c) Sparkling effect surrounding pokemon upon entering battle
d). Shiny sound sfx
So yes, paying attention at all times with said above guidelines in mind is useful. If it weren't we wouldn't see players with shinies in-game, trading/selling them. The thing is if you make a case that losing a shiny is painful then another argument could be made that says "Well, keep looking until you find another" but i'm guessing you want a mechanism that allows you to capture a shiny pokemon without any fails?
-puts on my clement spectacles-
Alright. Maybe you want the run button to be disabled or non functional when a wild shiny enters a battle? Oh my gosh! But that means i won't be able to run away at all!!
Yes, yes you're right but.. What about disabling the run button with a 10 second timer when a wild shiny appears?