I don't think it's a question of being able to tell what exactly X is up front so much as knowing that there is probably some X out there and that you should do due-diligence on what exactly your reward function is and whether exploits exist.
I can't tell you whether the TAS exploits-allowed world record speedrun of some particular game involves buffer overflows, faulty level geometry, or bonuses that were not meant to be stackable but I can say it's unlikely to resemble normal 99th percentile play.
I don't think it's a question of being able to tell what exactly X is up front so much as knowing that there is probably some X out there and that you should do due-diligence on what exactly your reward function is and whether exploits exist.
I can't tell you whether the TAS exploits-allowed world record speedrun of some particular game involves buffer overflows, faulty level geometry, or bonuses that were not meant to be stackable but I can say it's unlikely to resemble normal 99th percentile play.