It is clear from the Gemara that the Mishna’s requirement for a Yisroel to see the milking process is not absolute, but that being present in a position where he could stand up and see it at anytime is also sufficient, due to the fact that the milker is afraid to mix any non kosher milk into the milk in case the Yisroel will see him, and this is codified in the Shulchan Aruch, without any disagreement, the only conditions being that the milker is milking for a Yisroel and knows what milk is forbidden to him. [Y.D. 115/1]
The question is whether this idea can be extended further to its logical conclusion, in which case one could argue that whenever the milker would be afraid to mix non kosher milk into the milk, the requirement for a Yisroel to see the actual milking could be waived, even if he is not present at all.
This would not be annulling a decree of Chazal based on the assumption that is reason doesn’t apply anymore, something one is not usually permitted to do- It would simply be extending the Gemara’s ruling that the original decree against ‘Chalav Akam’ never applied to milk which was produced in the presence of a Yisroel, to never applying to milk produced under the conditions of “fear of Yisroel”, even without his presence, or by further extension , any equally significant fear at all! Such milk would in fact not be “Chalav Akum” at all, but would in fact be halachically “Chalav Yisroel.”
It was the Chazon Ish [Y.D. 115] who first suggested the possibility that government supervised milk might indeed be in the same category as milk produced in the presence of a Yisroel.
Later, Rav Moshe Feinstein [ Igros Moshe Y.D. 1/ 47] confirmed this view, basing his heter on 3 assumptions:
i. just like the Yisroel’s ability to get up and see what he is doing at any minute, government supervision and the accompanying fines and resultant loss if caught mixing any unauthorized material into the milk, creates a “fear factor” in the non Jewish milker
ii. The “fear factor” gives us clear knowledge that the milker will not mix any non kosher milk into the kosher milk
iii. Clear knowledge of something is considered as if one has actually seen it in many areas of halacha, including this one
It is factor iii, “clear knowledge” that nothing non kosher has been mixed into the kosher milk, that is the basis of the exemption from the gezeiro, the “fear factor” is merely what caused the “clear knowledge” in both the case of the Gemara, and the case of government supervision, and the Yisroel’s ability to get up (in the case of the Gemara), and the fines and resulting financial loss (in the case of the government supervision), are merely what causes the “fear factor.”
It follows from Rav Moshe that once one is prepared to understand that the Gemara’s exemption is describing an “exempt category” of situations, and not just a precise situation , it doesnt really matter what provides the “clear knowledge” and what provides the “fear factor” – main thing is that one can show HALACHICALLY VERIFIABLE “clear knowledge” that nothing non kosher has been mixed in the kosher milk in a given situation, and the laws of Chalav Akum might not apply to that situation.
Having said that, whereas we already have precedent for the “fear factor” being a HALACHICALLY VERIFIABLE source of “clear knowledge”, arbitrarily choosing one’s own sources for such knowledge would be unwise, and the Aruch haShulchan [Y.D. 115] indeed cautions against people being too clever and thinking that there is no cause for concern in any given situation, bringing a frightening anecdote to prove his point.
On the other hand, it is also important to note that Chazal only made decrees when they had a real concern with a significant chance of something going wrong: they need not make decrees to avoid farfetched scenarios of one in a million.
As such, it is not necessary to be 100% sure that nothing will go wrong in order to accept that a situation could have been excluded from a decree of Chazal- only reasonably sure, and then if there is precedent already for excluding similar situations from the decree, it is not illegal for halachic authorities to extend that precedent to the given situation.
As such, Rav Moshe Feinstein confidentally rules that milk manufactures under government supervision in countries where it is illegal to mix non kosher milk into cows milk and where transgression is punishable by fining or worse, is not subject to the prohibition of “chalav akum”, and in effect, has the status of “chalav yisrael.”
He permits drinking such milk without any hesitation but notes that it is fitting for “baalei nefesh” to be stringent and only drink milk prepared in the presence of a Yisroel, and that he himself was stringent as well. He stresses that one who is stringent should not look down in any way on those who choose not to be.
[ All Halacha blogs are summaries of my own learning and subject to further self-editing and user- correction- they are not psak halacha, unless specifically classified as such, and are for the purpose of study and discussion only]