I don't think people are manually updating the odds in real-time, more likely there is a central server using sophisticated algorithms that is taking care of the live sport events.
This is what happens. They have sophisticated algorithms and they have operators overlooking them. If something that happens such as heavy unseen weather changes, significant injury, or random tragedy, then the operator either pauses the live betting until they can make on the fly adjustments to the algo or bump the juice to cover the sharpness that becomes available.