There was one time where I accidentally called a Duplicate to gain an extra Curse when I bought a Gold because I didn't realize that my opponent had played a Swamp Hag on their turn. I really wish Shuffle iT made it way more obvious that Duration attacks like Haunted Woods and Swamp Hag were played, because I never notice them. Adding a little ant-sized icon to their VP/Villager/Coffers/Username bar really doesn't cut it.
I'm still mad that my opponent wouldn't let me take back what was obviously a mistake.
Haunted Woods and Swamp Hag put the icon into the bar of the affected players, not the player who played them. So when it's your turn and you are affected, it sits there in the central status bar.
Also with the new update, it shows you an (admittedly small) picture of the card you are gaining.
But I also often misclick, because I want to do Action X and I forget that before something else happens (like trashing for Cathedral the card you actually want to play).