coffee > And after he died his family checked the tefillin again and found a different passul
this for sure happened! As kids “learn” to be “better” than their parents, then most of parents’ mitzvos will be found to be pasul, as it is said above:
> his son tells him “ta, did you ever get that beketishe checked for shaatnez?
so, the chosid cared about bekesha, but neglected teaching his kid derech eretz (or sent him to teachers who think this is how you correct parents!)
A chachan, or even a tam, son should have said – Ta, how do you check bekeshas? Or, I learned today that bekeshas need to be checked.