It probably wouldn't have killed her outright if you had used empower for extra damage, but ultimately that's up to the DM. By mechanics though, she'd have a few more hit points before death, we'd need to beat her down to her -strength before she croaked.Wasn't sure if we still wanted her alive. Or if you'd get that bonus to damage.
He might not be being literal, but who knows. Either way, not much we can do about it now.That's some bull. We needed her to smack her around for infos.