It doesn't bother me, because I don't assume that attack hit. Here's how -I- justify it in fiction.
"The kobold attacks you, you barely catch it out of the corner of your eye. Does a 16 hit?" Notice: The success or failure has yet to be determined at this point. We know it will PROBABLY succeed, but "will probably succeed" != "Has succeeded"
"Suddenly I get an instinctive reaction, raising my shield to catch the bolt--I rolled a 2... making my AC 17. That shot is likely to barely be caught by my defense." Stopping attacks that should make their mark even has a name--it's called "Parrying" and it's a realistic thing to expect people to be able to get last minute reactions to peril.
Notice: NO RETCONNING. You have no more 'Shroedinger's Damage' than you did before the kobold rolled to attack in the first place. If your fiction describes it as having certainty before you have actual certainty, that's a failure of your fiction, not of the mechanic. If your fiction describes it as having reasonable certainty, then your fiction will be just fine.
You realise you're talking about a class that has an entire archtype based around "retconning" rolls?
I think you're overstating the issue. Many players find those sorts of abilities to be fun and enjoyable, because it gives them agency.
Agency is GOOD, not BAD.