you haven't said anything new here. Price must rise to account for destruction of a share, but market cap stays the same... (price / share goes up, price / fraction of company stays the same)
That is obviously not true and he's pointing out why - if the market isn't very liquid, in this case not a lot of sales, price can jump nonlinearly.
In theory if no one wants to sell shares of Apple during a buyback the share price will head towards infinity. There's always a price though that someone will let go of a share at.