Baloney. Lack of official status does not suddenly make you immune to the law regarding classified material. I work for a defense contractor; of course, not all of our employees carry security clearances. However the gub'mint specialists who come in each year to brief our employees make it quite clear: ignorance of the law is no defense. Those without a clearance have the same obligation to protect classified data as those with one.
Unless you can provide a specific legal statute (e.g., from the US Code), I don't believe that's true. It's certainly never been my understanding.
And in any case it's illogical: classified information shouldn't be in the hands of people lacking clearance.
You may be referring to a company policy - and certainly a cleared contractor would have many restrictions imposed by that status - but as for the individual uncleared person, not so.