How do elizabeth's comments about darcy at dinner cause wickham concern?

Wickham was concerned because he had told lies about his relationship with Mr. Darcy to Elizabeth, painting Mr. Darcy as a bad person who did Wickham a grave injustice by taking away his living, the church that Mr. Darcy's father had promised to him. Wickham did not say that he was the one who rejected the church and demanded from Mr. Darcy three thousand pounds instead.