Revealing mistake: The first morning the new Mrs De Winter is at Manderley, she goes to have breakfast, but when she attempts to pour milk into her coffee, there's no milk in the jug; she's just pretending to pour it.
Revealing mistake: After Maxim leaves a note, saying he'll be gone for the day and having him gone should be a welcome relief for her, the girl sits in the morning room, crying. As the camera moves away from the girl, some flowers on the right jiggle from being hit by the camera.
Revealing mistake: A lot of "Rebecca" is shot in a studio, even the driving and walking scenes, but in long shots, like when Maxim and Frank are driving back from London, to Manderley, in the "real" shot, you can see it's not Olivier driving the car.
Chosen answer: Maxim was previously married (unhappily) to Rebecca, who died tragically and under rather mysterious (and suspicious) circumstances, sparking rumors. Maxim thinks his new wife is referring to that, but she knows nothing about it and was only making an innocent remark, unaware of the rumors. The "rude, hateful" part probably refers to the "dull and gauche and inexperienced" comment - she probably thinks that is what caused his reaction, rather than the "gossip" comment, given she doesn't know the rumors. She is very young and naive and feels inadequate as the wife of a wealthy man. Maxim is older, intimidating her somewhat, and she was confused by his angry outburst.
raywest ★