Health,
I am not “trusting” any Rabbis. I understand the reasons behind the opinion that most Chareidim should serve in the IDF. I don’t understand the reasons behind the opinion that Chareidim should not serve in the IDF.
Daas Yochid,
“Infallible” means that you can’t make a mistake, it doesn’t mean you are right on occasion. If the Chazon Ish says a pshat I don’t understand, I break my head to understand it too. If, however, R’Elchanan also says a pshat and R’Elchanan’s I understand, then I am going to go forward in the Gemara with R’Elchanan.
If you have been m’kabel R’Chaim Kanievsky as your Rav then yes you are bound by his psak, whether he is right or wrong (unless it is k’neged an ofene mishnah). But I highly doubt that most people, even Chareidim, have been m’kabel R’Chaim Kanievsky as their Rav.
Additionally, even if one is m’kabel and they must follow doesn’t mean that the position is the correct one.