A chezkat kashrut does not depend on extraordinary punctiliousness, only that this Jew act as regular Jews do, says AH, puts on tallit and tefillin, prays thrice a day, washes before eating, guides his family to observe the Torah. [Ah, for the times when this list was the obvious minimum of what a Jew would do.]
Where a Jew is known to be lax, we start worrying. Rema in se’if two had said someone who violates the Torah le-te’avon, yields to temptation rather than acts out of principle, does not become a chashud. The Rema’s claim is not immediately understandable, since if the Jew did it le-hach’is, to make a point of his/her disobedience, s/he immediately becomes a min, outside the fold of observance, worse than “just” a chashud.
Taz therefore rejected this idea, Levush omitted it. AH in se’if fourteen thought Rema might have meant that if we see a Jew violate the Torah one time, it is enough to already stop us from trusting this Jew’s testimony (until/ unless he repents and restores his status), enough to require knife checking, if he is a ritual slaughterer, because that requires work and we already see his readiness to opt for the easy and comfortable. It will not make us think of him as an overall sinner.
To become a chashud, the lack of observance must be more regular.
There are Jews expert in arcane areas of law, whose observance is unassailable, whom we trust for all kinds of halachot. On less complex items, we can trust Jews who keep to the ordinary level of observance, or even sin occasionally, as many of us do. Should a Jew descend from there, become a chashud, we have to begin to consider where we may trust him/her regarding the permissibility of what s/he sells or serves, depending on how low s/he has sunk.
Certainly an issue with Pesach ramifications; we will, however, leave it there for now, come back to this, God willing, after Pesach. Next week, the minimal discussion of the mitzvah of sippur yetzi’at Mitzrayim, telling the Pesach story on Seder night, in AH.
