The situation I'm dealing with is a little complicated, so I'll explain it with psudonyms and then ask my question. Alice and Bob are both members of my team and report to me. Charlie is a person who works in another office for the same company. Alice and Charlie used to work together, so they stay in touch. Recently, Charlie told Alice that Bob is frustrated working with her and isn't happy with the quality of her work. And Charlie said these things in a chatroom with several other people in it. Alice is, understandably, upset and frustrated by this.
I believe Alice's story both because we have a good relationship and because she forwarded me instant message logs of the conversation between herself and Charlie. Logs can be falsified, of course, but it seems unlikely in this case. Clearly Charlie is gossiping and I need to talk to his manager about that behavior. What I'm not sure how to handle is the situation between Alice and Bob. I've pointed out that Charlie may have misunderstood or distorted what Bob said. That because we don't know what Bob said, it's important that we give him the benefit of the doubt. At the same time, this situation is going to keep bothering Alice until there's some sort of conclusion. The MT advice for conflict between directs is to have them talk to each other. That's a little difficult because Bob works remotely and Alice's emotions are, understandably, running high. So I'm worried that having them get on Skype and hash it out could cause more harm than good.
Because neither Alice or I have observed Bob doing this behavior, it seems inappropriate for either of us to approach him about it. But I also want Alice and Bob to be able to keep working together in harmony. So should I tell Alice to talk to Bob? Are there other approaches I could take? Any advice or suggestions are much appreciated.