Yes i'm ignorant of your imam's details about having all the knowledge.....so please enlighten me how do you know that he has all the knowledge and where is the proof for that?
I apologize that i am commenting on your question. I think your question is not valid.
Reason:
Sometimes believes dont need physical proofs. not because that we cant prove. its because WE dont have ability to SEE.
I think the above statement is very simple to understand the concept. however i am giving you the example.
- miner details of day Qayyamah we believe in are just though hadith but not proved.
All the knowledge in Quran; we believe in, but its WE who dont understand because of our own deficiency not because of 'that Quran dont have All knowledge.
Quran says Shaheed is alive; but we dont understand. however there is no physical proof.
Similarly:
It is a believe that Imam can have All the knowledge, it can be proven with "logic" / Aql. and the "need". but piratically it is not proven because we dont have the ability to test it.
For example: A teacher can test the student. a student can not test the teacher that how much knowledge my teacher has.? If the student cant test, the student can say that teacher have no are less knowledge. but its the student's ability which is stopping him not to test. (here i am talking about the real teacher, not those people who just start teaching with less knowledge)
Similarly:
Allah gave A lots of (almost All) the knoweldge to our prophet Muhammad (PBUH) but we dont have a tool to test it. Since we dont have a tool to test it. its our defeciency; and we cant say that He had very limited knowledge.
Same is the concept of knowledge with Imam. This is the not the problem. but the problem is who is the right Imam. ?