mik5,
It seems like you already have some opinions on this: https://www.theyeshivaworld.com/coffeeroom/topic/how-to-remain-a-ben-torah-after-leaving-kollel/#post-1329039
As far as how to dress when being reprimanded, I think one should dress just as he does every day at the office. Accept responsibility and apologize where appropriate, and be prepared with a plan of action to remedy the situation and prevent future occurrences.