How do you tell a harsh-but-real review from a planted one when all you have is the text?

Following up on a conversation here last week. Someone made the point that the cost of a wrongly removed review depends on how many reviews the business has in total, which changed how I weight errors in a small model I’m building for a class.

What I still can’t resolve: a genuinely furious customer and a paid competitor review can read almost identically. Short, one star, no specifics, emotional.

For anyone who reads a lot of reviews — is there anything in the text alone that reliably separates the two? Or does it only become obvious once you can see the account, the timing, or a cluster of similar reviews?

My model deliberately sees only the text and the rating, and I’m starting to suspect that constraint makes the task impossible rather than just hard. I’d rather find that out now.