Your co-worker is wrong.
John Roberts at CBS carried the memos to the White House at 11:00 a.m. the day that they aired them.
That's the first time they had seen them; after the show, the White House gave reporters who asked for them copies.
the way i understand it is cbs news gave the white house a copy a couple hours before the story ran; after the fiasco aired, cbs said the white house didn't say they were fake, which led them to believe they were legit; no word on how the white house should know what personal records from 30 years ago were legit or fake, and the white house did not say the information in the memos was accurate.