Actually, I suspect he’s implying that nobody’s trying to assassinate Harris because all the democracy-hating assassins are on her side, or she’s the one setting them up, or something to that effect.
It’s still the sort of slander which in a reasonable world he’d be called on, but that seems unlikely
For an emergency ascent, they’d probably have dropped more than two. They also probably wouldn’t have taken the time to type a message to the surface if it were going wrong that quickly.
It seems more likely to me that they were controlling their rare of descent. I’d expect them to lose a little buoyancy as the vessel compresses, so it seems reasonable that they’d drop the occasional weight as they descend.