That's really strange! When you make a mistake they should tell you exactly which clue it violates, so I'd be incredibly curious, if there's a bug, what kind of messages they tell you.
it was weird because even when i used the right answer, the third clue always told me something was wrong. I spun in circles for a few more minutes before thinking something was wrong with how the game loaded. I still don't know what caused it, but It was def something with the browser i use, as again, reloading the page fixed it, as it finally counted as right when i tried after the reload. not really a problem with your game, just my browser.
Edit: It's also possible my brain itself bugged out and tricked me into thinking i'd used the right answer when i hadn't.