Is a question mark needed after "kitchen"? I feel there might be as I imagine Bob has omitted "didn't you?" from the end of the sentence. If it was there a question mark seems like it would be needed: "Well, you saw the mess he made in the kitchen, didn't you?"
Bob: Tony's getting worse.
Rob: He is?
Bob. Well, you saw the mess he made in the kitchen? Now he's wrecked the bathroom too!