Aren't we taught to acknowledge the positive. I am tired of being called on small mistakes and never recognized for all the good work I do!
The old management style still prevails in many places
including my school as well.
Try 'killing him with kindness' so to speak - when he calls
you on the small mistakes, thank him profusely. Then test the
waters - follow with a question. "Mr. Principal, as you're
always so great as to help me with even small things like me
forgetting to hand in the field trip permission slips first
thing Monday morning, I'm wondering - what did you think of
the science fair my class did? The children and I put so much
work into that and we thought it came off great but what
insights might you have for me on that?"
It's a reminder to him that you do other things than field
trip permission slips but... it might also discourage him
from coming down on the small things if every time he does,
you hit him with a large question. Indeed, he might never
darken your door again. Try it.