But if the chalav stam is freash and the cholav yisroel is not, or the cholav yisroel is finished, he permitted to drink the cholav stam…l’chatchila.
You’re not using the word “l’chatchila” in the typical way. I can technically say that in a case of pikuach nefesh, it’s muttar to eat chazzir “l’chatchila”, but that’s not the typical usage.
Also, “baal nefesh yachmir l’atzmo” might very well mean even if it’s necessary to forego milk. I know people who are allergic or lactose intolerant and manage okay without it.