Fourtysix - Meeting Attendance

We're convinced this guy on the other end of our phone conference is sporadically ditching the meetings. He (his voice) shows up, usually at the beginning of the meeting, asks a few questions, and by the end of the meeting he is gone. The next series of phone meetings we are planning to do a XYZ (insert his name here) Check. This would be a single pointed question towards him with an anticipated 'no response' or ' he had to go' from his colleagues. We'll have to see how this goes.