Carla is standing near the beer spigots, and after a brief cutaway, she is standing outside the bar.
Woody calls the bar from the payphone in the bar, which is an outside line. Sam answers the phone at the bar, and after his faked conversation, hangs the phone up. That would have disconnected Woody from the line. Rebecca could not have had her conversation with Woody over the same line without dialing the phone again.