Caroline smiles with relief, knowing that there is still no proof of her infidelity.
She shouldn't have been so worried and should have trusted Amon when he told her to continue with the denial.
Before Amon left, he did tell her that her husband must be on his way, which surprised her. When she asked about it, she learned from Amon that her husband has hired a Private detective to investigate their affair, which worried her.
Amon reassured her and told her not to worry about it, and he had everything handled. She believed him at the moment and continued to do as she was told.
But when Kent brought her here to look at the CCTV footage, she became worried, thinking that Amon might not have had enough time to take care of the stored footage, but she was wrong.
Amon must have already known that her building's CCTV system was down and that is why he came over to fuck her.