charlie, those Rabbis were not Briskers. (Just related to them.)
Regarding pants, you could find a heter to whatever you want if you look hard enough. I’ve heard of so-called heterim from everything like uncovered hair, pants, mini-skirts… pick and choose Judaism. Heck, I’m sure you could find a heter to eat treif and be mechallel shabbos. Oh wait, the Reform and Conservative were already matir all that.