Just a guess, but "his work doesn't stop there" sounds like a point in the process, e.g. he's finished writing the report, but that isn't the end of it; whereas "over there" sounds like a physical location, in which case I have a hard time trying to picture what the sentence means.
I guess I'm picturing someone mowing a lawn, for instance, and he's at a distance part of the yard with an expanse still to go? Or, that same guy mowing next door and having three more neighbours' yards to tackle? Or even a scientist who has finished working over there in the lab but still needs to go somewhere else to publish results.