Q for @AcademicChatter - you inherited a grad student at the very end of their degree. They are now applying for jobs. They ask for a letter but you don't want to write one. They displayed some borderline unethical/sneaky behaviors during their time with you. What should you do?
If they ask you for a letter, the only ethical thing to do is to give your honest assessment of their abilities and character, in confidence, to their future potential mentor or employer. Otherwise 'recommendation letters' mean nothing.