Fruit for dessert

At the usual restaurant, the bill had a line nobody can explain: 'fruit'. That same night a golden whistle disappeared. Four people and one whistle: one person per row, one per column. Whoever is left alone with it in the same room is the one you're looking for.

Suspects

• Aurélio, the restaurant owner: He's served dinners to referees and club directors for thirty years. He insists they only talk about salt cod there.
• Beatriz, the waitress: She takes out the plates and brings back the conversations. She remembers who ordered fruit and who ordered something else.
• Celestino, the linesman: He came to dinner with the referee and only ordered a salad. The bill shows a platter of fruit.
• Dulce, the cook: She never leaves the kitchen, but always knows who's in the dining room from what they order.