Ubiquitin:
1) Are they different? Even if I benefit, presumably it’s still the issur of lifnei iver, so if we assume that even klapei the machshil, it’s muttar for the nichshol, it should still be muttar.
2) Isn’t it conceivable that someone would hold the same way regarding cholov stam as R’ Belsky holds regarding the eruv?
I will bl”n post mareh m’komos on both sides of the issue if I have time later.