Obviously not every teacher is 100% consistant 100% of the time, we are after all human , but I'd bet that the vast majority are because if you are not, your life becomes hellish. Just like parenting.
When kids walk towards me they have this funny nervous reaction, their hands fly up to their top buttons . And I quite like that in a funny sort of way, it is a mark of respect, and I respect them for it.
I allow kids to sit where they like at the start of term, and I warn them, that if they misbahave I'll move them. In any class there will be one ot two who will try it on, lets call them Atilla and Ghengis.
A and G choose to sit next to each other at the back of the class, and after a lesson or two the problems begin, lack of concentration, poor levels of work, disturbing other students. You then step in and warn, then you sanction, and because Atilla and Gengis may well not have parents who actually follow up on a threat (they did it once and the boys didn't like it, so they stopped) the poor bahviour continues.
So eventually, because you actually want to teach and not contain mini Barbarians, you make them sit alone, under your nose. The rest of the kids have worked hard, so they get to sit where they like. Immediatly the cry goes up from Atilla and Ghengis, 'You are picking on me , Miss'. Wheras I have simply responded to their behaviour and as a reasonable teacher responded to their particular needs. For the good of them, the rest of the class and to stop my blood pressure reaching danger point.
Atilla and Gengis will scurry home, eger to tell Mum and Dad how horrid I am and how I pick on them, the rest of the class can stil where they like, but these two angels have been singled out, because I am an old Harridan, with nothing better to do. And because Mum and Dad have long given into the path of least resistance, they belieave little A and G.
And that, ladies, is whey I keep a well documented behaviour log