Query about question "The entire affair only had..." [800]

https://www.gregmat.com/problems/verbal?problem=the-entire-affair-only-had


Why is there a contrast? I dont understand why we looked for opposites

“…only had the air of..” = how the affair appeared on the surface.

“…those who sought more info…” = what those who took a deeper look found

The contrast is between the initial appearance and what further investigation revealed.