Any Rov can only pasken the shailoh asked. It is a task to ask a shailoh correctly. I have encountered countless situations in which a particular psak was questioned, and it turns out that the there was information that was either distorted, withheld, or misunderstood. The ideal Rov recognizes the role of the one inquiring, and persists in verifying details in order to deliver the most emesdige psak. In reality, even the greatest can be duped.
I have personal knowledge of a shailoh that elicited a serious psak from Rav Moshe Feinstein ZT”L. The question posed contained seriously erroneous information, and there were huge stakes. (I cannot say more without providing identifying details and causing huge embarrassment to several people.)
Rav Moshe forbade the rav who lied to him from ever contacting him again. There are other ways to manipulate Daas Torah. It’s a huge chilul Hashem, and is a disgrace to all of Klal Yisroel.