The Steipler wasn’t against lying for “principle” in principle. There is plenty of proof for this (not to mention his promotion of Rabbi Shach), including his infamous letter on the Besamim Rosh. And I’m not even talking about the book “Shi’urim Shel Torah”.
Update
In the original article I then added:
“In the special collection of the Steipler’s letters to unmarried men dealing with problems of personal holiness (adapted from Kraina De’iggresa) he writes: It is a Torah prohibition of “Rechitza” to wash Keri off the flesh on Shabbos, even with regular water alone and no towel. Since this is false, I assume he was trying to stop his questioner from Aveiros this way. (This is from my notes; I’m away from a good library and I’ll try to find the reference later.)”