Howling:Sarah Jane's gang and the Tenth Doctor

It's shown in SJA "Death of the Doctor" that Sarah Jane, Luke, Clyde and Rani all still remember meeting the Tenth Doctor in "The Wedding of Sarah Jane Smith." But that story took place in a version of history that's now been negated by the effects of the Time Crack from Series 5 of DW (In that timeline, aliens were fairly common knowledge, but now those invasions have been totally erased from existence). So how can they remember things that never happened? EJA 15:53, May 11, 2011 (UTC)