THe approach of learning Halochos or Middos or behaviors from observing Tzaddikim's behavior alone is very common in our literature and is even rooted in Gemmorah (Brochos 62):
תניא אמר רבי עקיבא פעם אחת נכנסתי אחר רבי יהושע לבית הכסא ולמדתי ממנו שלשה דברים
It was taught in a baraita in tractate Derekh Eretz that Rabbi Akiva said: I once entered the bathroom after my teacher Rabbi Yehoshua, and I learned three things from observing his behavior:
Multiple stories describe Rabbis' behaviors and numerous conclusions are drawn without asking the source for explanations, clarifications or comments.
How Halachic is it - did our Rabbis themselves reflect on this subject?