Reply To: Causing Someone to Carry on Shabbos in an Invalid Eruv

Chein: Your “given” is wrong. As long as the other person has a valid opinion to rely on you can cause them to carry. R’ Shlomo Zalman used to give his famous example that someone who does not hold of the Heter Mechirah can give H”M food to someone who holds like it because they have a valid Posek to rely on. If the Eruv is actually Passul L’Chol Hadei’os then you may still be allowed to lend someone something as long as that thing has a permitted action that does not require carrying (see the Mishnayos in the end of Shevi’is; ask your Rav Lema’aseh).