Dan414 is a true optimist. Those wide eyes in the second panel indicate heightened interest not shock...But then shouldn't Dilbert be smiling in the last panel? ...oh I don't think he knows how to smile...someone please correct me if I'm wrong about that.
A totally clueless person and a savvy person might each have thanked the girl for the complement (albeit for different reasons). Dilbert has just enough of a clue to get into trouble -- sort of the psycho-social equivalent of robotics' "uncanny valley."
You can't assume that things didn't work out with this girl. The third panel could be taking place in the morning, after Dibert's walk of shame. After all, "blood-stained overalls" is also a bold look.
If only he had changed "I didn't have time to change" to "for that hit tv show", his world would have changed forever. But then, if he could do that, he would be in management or marketing, not engineering.