Question: A Hanfee imam rectifies himself by the correction of a Shafee who was looking in the Quraan. Is the salat of the imam and the congregation valid?
Answer: According to Imam Abu Hanifa to read from a Quraan nullifies salat because of the excessive movement required in picking up the Quraan, flipping through the pages and looking inside. To give luqma (correct the Imam) whilst looking in a Quraan will also make salat void. Since the muqtadi (one who is behind the imam) in this case is a Shafee, salat will not be void. However to do so is makrooh. One should correct the imam from memory.
According to the Shafee mazhab, the intention of the muqtadi will be taken into consideration; therefore if the muqtadee is a Shafee his salat will be intact. However, one should keep in mind that to adopt this makrooh (disliked) method is reprehensible to say the least. One should make a concerted effort not to practice on this. As far as possible one should attempt to give luqma from memory. In a similar manner one should endeavour to abstain from excessive movements in salat.
According to the Shafee mazhab, if one does something in salat excessively that is not part of salat, then these excessive movements or actions will render one's salat null and void. On the other hand, if these actions are very seldomly done, then this will not invalidate the salat. The difference between excessive and insignificant movements in salat is based upon the opinion of the general masses, i.e. whatever they deem to be excessive will invalidate the salat and whatever they deem to be insignificant will not invalidate the salat.
In conclusion, one should try to avoid excessive movements when looking in the Quraan. If one picks up the Quraan with only one hand, then outwardly it seems as though this will not be makrooh.
Fatāwā Dārul Ulūm Zakariyyā, Vol. 2, Pg. 501-502