Did you set up the Connect session, or were you a participant?
There is a Participant's pod that can be shown or hidden by the host, and you would see the login name there during the session if the pod were enabled. Meetings can be recorded by the host, but often are not. If it was recorded, and if the host gives you a link to watch, you may still be able to see the name he logged in with.
If all that fails, you have to do it the old fashioned way. Ask the host. Ask the HR department. Ask the other participants.
The best way might be to ask while the meeting is still in session.