Fox Fox, I've never heard that.  Perhaps it's a regionalism or even something peculiar to him.  "How ya going?" is certainly common.  "What's shaking?" was popular a few years ago too. 

Some recent observations that I've made include:

(1) Students need to be praised.  Those who deserve it least may need it most.

(2) I saw a native speaker teacher make a face (careta) while listening to a student.  Later I learned the student had been devasted.  "Why bother talking in the classroom if my bad command of (foreign language) is hurting the teacher's ears?" 

(3) There is a difference in English between "mistake" and "error".  Errors are the result of carelessness, nervousness, stress, etc.  Mistakes, on the other hand, are the result of not understanding a concept, rule, etc.  If I misspell "that" TAHT, it's an error, not a mistake.  I know how to spell "that".  If I don't spell it correctly, you can call my attention to it, but giving me a 30 minute lesson on spelling it is unnecessary, a waste of your time and mine, and demeaning.  Errors seem to multiply in conversation because of the stress under which the student speaks.  As soon as the student says "the cow are", he probably is aware of it and mentally corrects himself.  If the teacher is too critical, the result will be more stress next time, and more stress leads to more errors.  If I say "Me store to go morning this," chances are the next lesson plan should address the problem.  I've failed to understand some basic grammar rules.

(4) Teachers need to listen.  This sounds so obvious, but some teachers seem so "hyper" that they react too swiftly to what they perceive as a problem, and this leads to stress and greater pressure on the student to be perfect in something he is learning and not yet mastered.  Let the student talk!  And on the subject of stress, I think teachers should always be very constructive with their criticism.  We have all heard teachers criticize in front of the class a student's bad handwriting, lack of progress, etc.  Negative criticism is petty and unprofessional. 

I'll stop here before you are bored to tears.  Being a teacher isn't easy.  Being a good one is a challenge.