Assalamu alaikum wa rahmat Allahi wa barakatuhu
Barakallahu fikum

We know that one of the principles of recitation is to read as you read to your shaykh or as he read to you. My question is what do one do if  one read in a certain manner which goes against the classical text as one questioner asked about the “ra” in the word “irbati” or worse what do you do if someone has received ijazah in this manner. Could you please explain what ibn Jazeriy means in his tayyibah “wal yajtahid fihi wa fi tashihihi alalathi nuqila min sahihihi”

Wa alaikum assalaam wa rahmatullahi wa barakatuh,
There are three basic principles in the passing down of the Qur'an from generation to generation outlined by Imam Ibn Al-Jazaree in his prose for the ten grant qira'aat: At-Tayyibah.  Immediately following the lines quoted in the question, he states these principles:
1.  The way of reading has to agree with an accepted form of grammar in the Arabic language.
2.  It has to agree with the writing of the mus-haf, or close approximation.
3.  It has to have an authentic chain.
If these three principles are met, then in his words, may Allah be merciful to him," huwa Qura'nu".  Meaning then it is part of the revelation and part of the "seven ahruf" ; if one of these principles is not present, then it is not considered an authentic way of reading.

We have two ways of finding if a particular way of reading a word has an authentic chain, and we should use both.  One is that there is an authentic chain of transmission from the Prophet to the sheikh/sheikhah wtih the reading as he/she has taught.  The second is there needs to be written documentation of this way of reading, the older the written documentation, the better.  One may find something written in modern books that has no source in the early books of tajweed, so we should always look for early sources when researching tajweed rules or ways of qira'aat.

A student who finds themself in the position of questioning a way or rule used by his or her sheikh/sheikhah should very politely ask where this can be found in early books of tajweed.  The student should be asking this out of a genuine quest for knowledge not just to argue or try to challenge their shiekh/sheikhah.  It is not part of proper manners to ask a question just to ask it, push your opinion on to the teacher, to hear ones voice or see their words written, or just try to challenge a teacher.  Politeness and respect of the teacher should be observed at all times. 
If no text can be found, the student then should ask others in the postion of knowledge (scholars), without mentioning their sheikh/sheikha's name if at all possible, to find if there is any source for what they have been taught.  If none is found, the student can then reject this way of reading with no need to confront their teacher. 

There are many works on the manners of students of knowledge, and although we know the questioner is well aware of them and employs these manners, may Allah reward them greatly, we wish to let the visitors know that they can find some guidelines in the following:
There are many other written guidelines for manners in the English language.  We have listed one below:

Wa asalaam alaikum