"...No, we were — I — we'd actually left already, and we were going to the car to go to another casino, and that's when we got that phone call."
There it is! Deepak had already called him and actually arrived at jorans location when paulus called.
Yeah...I already knew that. But, the reason Deepak was even there at all, I think, was because he knew Natalee's family was there and they were looking for Joran. Joran said himself that it was unusual for them to hang out together two nights in a row.