JayMatt:
The Lekach Tov explicitly states they did not sin. I am inclined to believe the Lekach Tov, not your assertion to the contrary (though there may have been SOME in Klal Yisrael who did adopt the position you mentioned, according to other mefarshim).
Again, as I posted a while ago and again on Friday, he says they DID NOT sin. That means there was no aveira. Yet, he says, Kivan sheNitan DID apply.