I must have read it incorrectly:

https://www.justice.gov/sites/default/files/olc/opinions/200...

> As these opinions confirm, a presidential pardon removes, either conditionally or unconditionally, the punitive legal consequences that would otherwise flow from conviction for the pardoned offense. A pardon, however, does not erase the conviction as a historical fact or justify the fiction that the pardoned individual did not engage in criminal conduct. A pardon, therefore, does not by its own force expunge judicial or administrative records of the conviction or underlying offense.