That which one is allowed to be ovar an issur because of Kavod HaBrios is it even b’kum v’aseh or only by a case of shav v’al t’aseh?
Answer:
In priciple, the Gemara writes that it is permitted to transgress a rabbinic prohibiiton for the sake of kevod ha-brios (human dignity), and likewise to transgress a Torah prohibition, but only when the latter is by way of shev ve-al ta’aseh (passively, and not actively). See Berachos 19b.
The Rambam does not mention the transgression of a Torah prohibition because of kevod ha-brios, yet writes that only an explicit Torah law overrides kevod ha-brios (see Sanhedrin 24:10; Kilayim 10:29).
The categories of “passive” and “active” are liable to different interpretations, as we find in later authorities. A famous case is the discussion of the Sha’agas Aryeh concerning the wearing of tzitzis (is “wearing” considered active or passive?). Another is a case raised by the Terumas Ha-Deshen concerning a Kohen who finds himself in the same tent as a meis.
Best wishes.