He could have been lying about the Admiral calling him.

[Shaw points out, her eyes on Root in the hammock. Now that she's settled, it would make sense to go off and get cleaned up herself, if she can find some running water.

But instead, she eases herself onto the hammock too, nudging Root over so that she can fit.]

The Admiral told us to hang on tight, but he didn't say crap about sending some stranger to pick us up. The Barge wasn't damaged, right? There's no reason he couldn't have grabbed us himself.