Inc.com columnist Alison Green answers questions about workplace and management issues--everything from how to deal with a micromanaging boss to how to talk to someone on your team about body odor.

A reader asks:

I manage a large medical practice. One of my leads gave her notice about two weeks ago. At the time, we congratulated her because she has gone through some rough times lately, and we were excited that a new job would give her a new outlook, plus a nice raise. She told us how much she loved her job and said she just needed a change.

Since her notice was given, she has done nothing but badmouth my director and me to other staff. A few staff members have disclosed this to me, and I have been stunned at some of the baldfaced lies she has told -- most of which were witnessed by other staff. It got so bad that I spoke with HR to find out if we could let her leave earlier than planned. They understood but said to let it go and play out.

It became so toxic (to me personally) that I spoke with my director and decided to take three vacation days, the last three days she is in the office. Today I hear that was another thing she trashed me about to HR in her exit interview -- I didn't say goodbye to her.

I had planned to either call or text her on her last day and wish her luck because I really want to do the right thing, but honestly it wouldn't be sincere at this point. Should I let it go or send a quick "take care and good luck" text before she leaves (so I have it in writing)? Also, do I just wait and see if HR says anything about the exit interview, or should I address it head-on?

Green responds:

It's understandable to be frustrated by someone who's behaving this way! Frankly, I would have talked to her about it and suggested you wrap up her transition earlier than planned (while still paying her for her full notice period), so she wasn't sticking around causing disruption in the office. I'm not thrilled that your HR department stood in your way on that.

But you're the manager, and you should take the high road. That means you say goodbye to an employee on the last day you'll both be in the office before they leave. You do it because it's the professional and mature thing to do, and because there's no reason to hand someone a legitimate thing to complain about to others. (And "my boss didn't even acknowledge me on her last day in the office during my notice period" is a legitimate beef, and it won't make you look great to people who hear it.)

So yes, I would contact her to wish her well before her last day. But don't do it by text -- that screams "not invested." You should call her, wish her luck in her new job, and thank her for her work while she was with you. (If you can't stomach saying that last part because of these last couple of weeks, it's fine to leave that out.) And if you really feel you need written documentation that the call happened, you can email her beforehand to schedule the call ("I'd like to touch base with you on wrap-up items and say goodbye before you leave -- I'll plan to call you at 3 p.m. today unless you tell me another time is better").

Aside from all that, it's also worth reflecting on what happened here. I take you at your word that what she's telling people are lies, but do you have insight into why she's doing that? Was there tension in the relationship previously? Did she have grievances that never got addressed? Were they legitimate? If they weren't, did someone try to hash out the differences with her? Were you blindsided by her behavior these past couple of weeks, or were there signs of it earlier?

The way this has all gone down means it's likely that one of these is happening:

1. She was always a problem employee, and it was never addressed. That probably means that you need to manage differently in the future because you don't want problems festering on your team.

2. She's reflecting back to you real issues on your team that need to be dealt with. She might be frustrated by legitimate problems and expressing it poorly/immaturely. (If you had to guess what she's really upset about, what would your gut say? Sometimes that can point you in the right direction.)

3. There's some major misunderstanding/miscommunication somewhere.

I don't know which of these it is, but you don't want to just ignore this once she's gone -- take it as a flag that at a minimum there's some reflection to do on what happened.

Want to submit a question of your own? Send it to alison@askamanager.org.