I thought the butler heard him say it then tells the reporters etc...Not G. Ivingname said:This is hard to explain, so I will just give an example:
How to shut up an up tight film critic in a second.
If they are ripping on one of your favorite films for plot holes, ask him/her who heard "Rosebud."
Now, how do you shut up any group instantly?
EDIT: Yea, The Butler did it!!!
'From the Kanes' butler Raymond (Paul Stewart), Thompson hears how Kane trashed Susan's room after she left but stopped when he came across the snowglobe (which we recognize from the deathbed scene). As Kane pocketed the snowglobe, Raymond heard him say "rosebud." Raymond has no idea what it means. However, he tells Thompson that he was in the room to hear Kane say "rosebud" again just before he died.' -Taken from the IMDB plot summary.