Continuing its discussion of the status of a sacrifice that becomes disqualified, the Gemara on Amud Aleph discusses an interesting case in which a sacrifice was found to be a tereifa only after the blood was sprinkled, since examination of the internal organs occurs later:

“Rabbi Chanina holds that in the case of an animal that was found to be a tereifa due to a wound in its intestines, the sprinkling of the blood nevertheless effects acceptance, because the wound was unknown at the time of the sprinkling.”

The Rosh (Chullin 87:37; see also Shach YD 93:21 and Peri Chadash 21) uses this as proof of a principle: Halacha only responds to known phenomena.

For example, if a non-kosher substance falls into a pot, it is normally nullified by sixty times permitted substance. If at a later time more non-kosher falls in, the nullification may use the entire mixture as permitted substance to nullify the new material. However, if non-kosher fell in initially but one did not become aware of it until a second batch of non-kosher was added, then the permitted substance must be sixty times the sum of both prohibited substances.

This is another clear example of the power of subjectivity in Halacha, and how awareness determines outcome more than objective facts, as discussed in prior Psychology of the Daf posts for Zevachim 98 and 100.