To be critical and to ask them questions. because, if do not ask them our critical questions, they will not keep on thinking on critical things. Additionally, we don't have capacity and scopes of thinking many critical situations and their solutions that our Scholars do have. If we don't ask them, they normally will not be concerned about them. so, it is our duty to ask our scholars to work for us, thereby to serve us and thus serving our Lord Almighty.
My additional thinking with it is --
All those scholars are human being and they can never cover all perspectives of thinking and can never experience the situations that people do. so while they grow in knowledge, they are excellent and they know many things and sometimes masters in certain fields. but they may not be master in all perspectives so there may be some shortcomings, less amazing portions in their ideas and contributions. that doesn't nullify them nor a cause to be treated as flawless.
So, it is our mind, which will be keeping on respecting them with criticizing their limitations. but not crossing our limit of being modest and respectful -- this is an essential quality of any learner and the absence of it eventually nullify the eligibility of being a learner.
i think and found it is important to know *where* goes the limitation but may be that attitude is not to be 'khutiye khutinati jana' (spying to know). i knew nobody is perfect long way back in my life but it didnt work on being hurt and confused about people i value much. i was in darkness before developing the attitude of knowing *where is the limitation* with respectful critical mind.