Since no one knows what was discussed,everyone is just guessing and speculating.
What was discussed is irrelevant. There is the appearance of interfering with the investigation.
It doesn't really matter "what was discussed."
In these intimidation maneuvers, it's not the literal language that is used to convey a threat.
Remember Kathleen Willey's description of the way the message was conveyed to her? One day Willey was out for a walk near her home in Virginia, when a complete stranger came up to her and asked about her children ... mentioning her children by name. And the stranger also said something innocuous about Willey's cat. A few days later, the cat disappeared.