It's nice seeing how Clark's anger didn't override his concern over Lois' well-being. He calmed down considerably when he saw she wasn't in any shape to drive. Seeing her so distraught made him more likely to believe her. She wouldn't be so upset if she was only playing games with his emotions. So good reason for the transition from anger to acceptance!
The revelation seemed a little vague. Lois must have really been on the ball to go from "I was there" when he could simply have been hiding somewhere nearby to "Clark is Superman." On the ball is something she usually isn't when it pertains to her personal life, especially when in a distraught state of mind. So I kept waiting for additional hints.
