I-140 denied after RFE. Is the denial reason always tied to RFE?

We are waiting to receive the official notice. However, in order to prepare ahead of time, I am wondering in the meantime if the reason I-140 was because the response to RFE was not sufficient. Could it be tied to anything else? This is for PERM based EB2.

Also, we need specific guidance in our case that even our attorneys were not able to help with (which might be why RFE response wasn’t well received). Is there someone from USCIS who can guide?

Thanks