"This is not just any cell, but a cell capable of reproducing a human embryo," he said. He added that, in effect: "a second embryo is being destroyed".
Raises some interesting philosophical questions then. Could someone simply grow 10 billion of these cells? Would that therefore mean over half the human population of Earth existed in their lab?
No...eventually, with more generations (or cell divisions) -- beyond the number that this researcher waited, these cells will loose their totipotentcy and become pluripotent cells. But then the pluripotent cells less desired to the "embryonic stem cell researcher" because they cannot become "any and all" human tissues.
The bishop is getting a bit ahead of himself there. Eventually I expect it will be possible to grow a whole new embryo from one blastomere, but as far as I know, nobody has done it yet, even in animals. A contigous pair of blastomeres can often develop into an embryo and beyond, but not a single one.
And yes, by some people's definition of "person", the lab in your scenario would indeed contain over half the human population of the Earth. Which is why the notion of regarding these cells as "people" is not accepted by most scientists who work with them.