Flying for Fun-- great stuff. I agree checking for understanding is a very important part of instructional technique, the amount of checking varies according to the ability of the student and of course the instructor too.
You reminded me of that type of student who finishes every sentance for you God that is annoying isnt it?
Its a little bit of the opposite in the examiners forum sometimes with the stude understanding what you are saying but just not accepting your reason for the criticism. The big problem is time, if you mention 6 items you can open the situation for a 6 point debate.
I will give an example where I failed a stude for overall performance and one of the criticisms i made is that I did not detect him make any control input to align the aircraft with the centreline while making a crosswind landing. My feet were very carefully and lightly placed on the rudders and at no time did the student remove the drift, he just allowed the aircraft to land with the drift on, no big deal only 15 knots xwind but I was specifically examining xwind technique--he would not accept this, (he of course did not detect the drift) lengthy debate, wanted to do it again etc etc