"Laid finger on" is an idiomatic expression which refers to the act of pointing out, identifying or finding something. As a result, it is often used in contexts where we are trying to locate or identify specific objects, people or situations. The opposite of identifying or finding something is losing or misplacing it. Therefore, the antonyms for "laid finger on" could include "lost touch with" or "misplaced." Other antonyms could include "failed to find," "overlooked," "missed" or "lost sight of." Each of these antonyms represents the opposite of "laid finger on," and can be used to describe situations where we have been unable to identify or locate something or someone.