Audio overlap on recording

Hi all....we're just at the beginning of using Connect for webinars and have been doing some recordings of presenters with some slides as part of that.

The issue that came up with one we just did is that the presenter audio (two presenters, different locations) overlapped on the recording of the presentation. IRT, one wrapped up, introduced the second and the second advanced the PPT to her slide as she began. All fine.

In the recording, her audio began before his started. I hadn't seen that before and was wondering what happened. The layout being used didn't change, so I'm kind of stumped. Both working with hard-wired headsets on laptops using solid wireless connections. Any thoughts?

Thanks