Meaning of "he knew he looked insulted"

Question

"Maybe you should take a few things out of your pocket before you go," said Mr. Carr.

Alfred replied, "What things? What are you talking about?"

"You have a compact and a lipstick and two tubes of toothpaste, Alfred."

"What do you mean? Are you calling me a thief?" His face got red, and he knew he looked insulted. His boss nodded his head and Alfred became frightened.

Source: adapted from Discovering Fiction: An Introduction, Chapter 12.

I don't get the meaning of "he knew he looked insulted" clearly. Does it mean that Alfred knew that he looked like a fool and from his appearance everyone could guess he is a thief?

Answer 1

It means that Alfred knew that his expression made it clear that he was offended that someone would consider him being a thief. It does not mean he looks guilty, just that he doesn't like being called it.

Answer 2

You have misquoted this. It is important to quote exactly as the original is easier to understand.

"What do you mean? Are you calling me a thief?" Alfred's face got red and he knew he looked insulted. Sam Carr's eyes were shining behind his glasses and his lips were moving underneath his gray mustache. He nodded a few times and Alfred became frightened.

Alfred is young man, a teenager, who works at a drug store for Sam Carr, the manager. He has been stealing from the store and in his pocket are a few small items, like a tube of toothpaste. Sam has asked Alfred to "turn out his pockets".

The text says that Alfred looked insulted. This is because it is insulting to call someone a thief. But I would have written "Alfred knew he looked guilty". Perhaps the writer uses "insulted" because it is a more common word than "guilty".