But if the goal is to empty your hand, not playing a card would be self-penalizing, wouldn't it?
Yes... but this is NOT a way you can "screw your neighbor" by passing a card. You MUST play a card; if you can't, you draw a card.
Is it a different rule than the original Sherlock Holmes: The Card Game?
I really don't remember; it has been over a decade since I've played that game!