How hernia surgeon could miss hernia?

Yes, it is possible to miss a hernia during laparoscopy, unless the peritoneum was take down and the fascia level itself was visualized.

Not sure where or what the picture is showing as there is no obvious Spigelian or incisional hernia seen. Perhaps point to the area?

Spigelian hernias are very difficult to see or palpate unless they are large.