The player is playing their game.
You stand before the accused. Two men, each with evidence pointing at them but nothing definitive that you've found.
The first is Gerard, a man of principle, soldier at heart. He'd given his life in service to his country. Once he came home, his wife accused him of having cheated on her during his time at war. She'd heard the reports of rape and was understandably doubtful of her husband's loyalty, however she wouldn't allow herself to be swayed from her position. Gerard left the home he'd given his bloody money for without another word and came to two days later in the gutter, clutching an empty bottle. She'd been killed that second night.
The second is Ferdinand, your assistant. A cursory examination of the woman's personal life revealed that even as she accused her husband of disloyalty, she herself had slept with Ferdi. Soon after Gerard had been sent away Ferdinand had discovered that she wasn't as single as the bored woman had let on. He too stormed out and he too had only woken up days later in a gutter, clutching his own empty bottle.
Whodunit? You are given the choice to decide. If it was Ferdinand, you wouldn't want someone this unstable on your side and if word got out you'd be suspected you were covering for him, tarnishing your reputation.
The player knows Gerard is an extra and doesn't really matter to the story. Beyond that, they like Ferdinand a lot and want to get his good ending, one where he might finally find true love like he'd always wanted, one which might end in him thanking the player for being so morally good and not doubting him. Maybe that love could even be between him and the player's character...
You decide that it must've been Gerard. Even if it wasn't, you'd be there to keep Ferdinand in check. The morning after you've declared your verdict, Ferdinand is found in his room, having hung himself out of guilt, evident from his suicide note. You had let him down with your naivety.
The player is frustrated. How were they supposed to know this would happen?! They did the morally good thing! How did the developers think this could ever be a good idea?!