We also use it to apologize when being rude without meaning it. Example : you make a remark without really thinking of it because of your professional habits

We also use it to apologize when being rude without meaning it. Example : you make a remark without really thinking of it because of your professional habits (ex: you should be doing things that way, or going straight to limit-cases or counter-examples) that would made sense in a professional context, but that is not acceptable outside. You would apologize saying "I am sorry, it is a déformation professionelle"