Indy says at the castle,
"... (Elsa) Ransacked her own room and I fell for it."
From this we're supposed to accept that Elsa ransacked the rooms (including her own) to try and find the Grail Diary. But Elsa appears to be in the bathroom when Indy brings her attention to the room-ransacking. She takes the opportunity to stop a record playing really loudly.
As the audience are we supposed to assume that the record was so loud that she didn't hear the room being ransacked behind her? Why would Indy believe that? Wouldn't the furniture being toppled provide enough ruckus to alert anybody in the room?
The other thought is that she somehow got into the room and to the bathroom without noticing that the room had been ransacked which seems equally preposterous. In either case, it seems ridiculous that Indy would fall for believing she entered the room without noticing its state or that the room could possibly have been ransacked with her in the bathroom unable to hear it.
A third possibility would have been that Indy went directly to Marcus Brody's room and didn't see his room until that moment when he opened the door. He is wearing a robe but I suppose he could have gotten that from Marcus' room. Elsa, on the other hand, still had to get inside the bathroom and get a robe on herself. Does that mean the bathroom had a direct door to the hallway? That's the only way I can imagine her story holding water at all about not noticing that her room was ransacked.
It still seems awfully convenient that neither Indy or Elsa stepped foot in their rooms before the scene where Marcus and Indy discuss the map with no names.
Without a credible reason for not knowing her room was ransacked, it seems Indy was being a bit dense in not suspecting Elsa from the start. Since we know Indy to have pretty sharp wit, is there a better explanation for his being duped by Elsa's pretended surprise that the rooms were ransacked?
Is there a better explanation for the rooms being ransacked and Elsa's attempt at being ignorant of it?