A woman is sitting in her hotel room when there is a knock at the door. She opened the door to see a man whom she had never seen before. He said "oh I'm sorry, I have made a mistake, I thought this was my room." He then went down the corridor and in the elevator. The woman went back into her room and phoned security. What made the woman so suspicious of the man?

“The man looked suspicious.”

The riddle does not specify anything about the man's appearance or demeanor that would make him suspicious; the woman's suspicion is based solely on his actions.

“He was carrying a large bag.”

While carrying a large bag might raise suspicion in some contexts, the riddle does not mention the man having a bag, and the woman's concern is focused on his unexpected behavior.

“He spoke with an accent.”

The riddle does not provide any information about the man's speech or accent; the woman's suspicion arises from the illogicality of knocking on his own door.