That crossed my mind really early on, as it was never made clear who Seferi was in the phone with (and once mentions that whoever he is talking to is using a new number, right when Marina has zipped off to Crete without her phone). Later it seemed to indicate he was talking with Joel, but still there could well be another member of their group - it did look like bald guys gun was the same gun Seferi shot Joel with, as one possibility.