High insight rolls reveal hints observed about mistruths. The lie/s could be singular, many, exaggerations or omissions. They may also be emotions disguised. Colour (description) could be added to flesh out of a high Insight roll, perhaps you notice the parched lips of the speaker and thus you offer them water - whether you use the water threaten, tempt or actually as a act of kindness to entice the truth.
Insight may offer than just, this is lie - it may reveal a flaw, ideal or bond you can leverage.
High perception may not necessarily reveal the trap, but clues of a trap, additional colour (description) which may assist with a puzzle, sense of being-watched, it could even be used as a flaw (paranoia), a sense that something is off with this reality - that requires further investigation.
What I mean to say is, my experience has shown that the binary use of skills creates less excitement and doesn't facilitate for a greater immersive experience IMO. I do not claim to do the above with every roll, maybe not even 50%, I wish I did more, but is it certainly great when I do remember and am able to do it successfully.