Say a buyer made you angry and you were sarcastic, insulted him, rude, etc. So the buyer complains to Trust & Safety and you get an account warning.
So days without warning means days without getting a warning, it’s that simple, days without getting in trouble.
If you don’t insult, minimize the sarcasm, do your utmost to be professional instead of getting personal, you won’t get in trouble even if the buyer complains about you. Fiverr doesn’t just assume you’re guilty because someone complained. Fiverr will look at the conversation and what was said.