That is worldwide. Does Apple employ people overseas for engineering?
In the US, Apple employs ~50,000, of which 28,000 are retail and 8,000 are customer support... leaving 14,000 white collar workers for marketing, management, finance, HR, support, design and engineering.
Still a lot, but we don't know how many are engineers and designers.
He's probably right. The original iPhone development group was supposedly around 100, and that included secretaries, etc.
Anyone who works on software knows that more people is definitely not better. A small team of experienced people will create more (and better) code than lots of newbies.
In fact, Apple has often remarked how they're still run like a startup (meaning low personnel count)... and there have been many reports of engineers from other departments being dragged into iOS 7 development only temporarily.