Same. I didn't see anything offensive in @iserith 's examples, as a player or as a DM.
@iserith and I have talked about this before, and I think they have a specific preference for not telling characters what they think (with an exception for things like mind-control, IIRC). The boundaries are perhaps a little unclear, looking from outside, but it seems pretty consistent to me.
Personally, I'm reluctant to narrate actions (the to-hit) but more willing to narrate results (the kill), and I'd probably want to roll the Wisdom (Insight) roll myself or ask for a passive value and roll for the NPC myself (latter seems preferable as I'm writing this), and narrate the result, being willing to make the result explicit if the players around the table didn't seem to be getting to the correct conclusion (where "correct" means "consistent with the dice result).