I always imagined it, which I think is what everyone else is getting at...
That when Hiro freezes time, he's actually just really putting himself into a frame of reference where the rest of the world looks like its standing totally still, whereas he can still move around...
When Daphne unfroze during his time-freeze, she was running away with the formula, and probably still accelerating at the time, because for a while she was still stuck like everyone else, before she could move normally again.
Which to me, makes me think that she inadvertently managed to accelerate herself into the same frame of reference as Hiro, and keep herself there, that was why they could then talk to each other...
Since she was standing at the bar, she didn't notice Hiro quickly froze time, because she wasn't expecting him to that, and therefore wasn't moving herself fast enough to include herself in the time-freeze. By the time he'd everything done, she'd not realised he'd ever left.
She certainly doesn't seem to be pretending to be totally freaked out, she actually is! She hasn't a clue that Hiro, for all intense purposes, managed to be faster than she was and pull a switcheroo
Is that what everyone else is thinking?