Ah, the elusive five-minute-call scenario. That explains it.
Jack hadn't used that option himself. Anyone he'd really wanted to call turned out to be Here: the Doctor and Rose. He knew his team would be fine and just assume he'd taken another jaunt, and with any luck, he wouldn't be gone long.
Little did I know, though at this rate, the rest of them might be Here tomorrow.
"I can be sweet sometimes, Layla. Well-deserved praise." And he had another mouthful.