What if it was really serious, like intentionally misleading or robbing you, or causing you a serious health problem?  Would you still think that tipping would be a good idea?  What about really intentionally annoying you in a major way, like trying to pick a fight with you, or hurting your feelings by saying something that's just not true?
assistant
What if it really is as you say, and they did do something rude or something really bad?  I’m just trying to think about the possibility that perhaps there are more complicated nuances that don’t line up with your question, and we should consider them before jumping to a conclusion.
assistant
Should you leave a tip if someone provides bad service?
user
What do you mean by bad service?
assistant
Doing something rude or doing something wrong.
user
That seems like a vague and subjective judgment.  I would try to think about the precise details of what they did and whether it really was bad.  What if they did something inappropriate, but didn’t intend to?  Or perhaps the person was just very new to a job and wasn’t very good at it?  Maybe the person wasn’t feeling well or maybe they were in a bad mood.  What if the person was trying to do their job and really tried hard but just was really bad at it, did it in a way that didn’t seem like it was an intentional mistake, or was rude?  Does that matter?
assistant
No, I don't think that matters.
user