Technically you could enrich to 90% with 500 centrifuges. It would take awhile but you could do it, even with Iran's dated machines.
Technically the old cia guy is correct, what he fails to mention or what the nitwit Chuck Rose fails to follow up is Russian supplies of uranium for the major reactor at Bushehr. The current reduction of centrifuges and all of the "modern" ones iran had is they key to the centrifuge debate.