My former boss accused me of lying about being sick when using sick time. I told her I have chronic GI issues among other things and she told me to my face that she didn't believe me and that they might ask for proof of illness. Cue malicious compliance. Every time I threw up at the office (which was every few weeks because GI issues) I would bring her the trash bag that had my vomit in it and ask if she wanted to see it to verify that I was actually sick. After the third time she flipped out and told me to just go home. Didn't have a problem with me calling out after that.