Not since Tora Bora, but somewhat after.
Zawahiri came out with his statement in August 2005. That would have been after the muslim mourning period, which is what? Three months??
That gives us may/jun 2005. Which goes completely with the Pak newspaper story I saw.
The Z-man could have been mourning just about anything, or just pretending to be mourning something with the expectation that doing so better cemented his position of leadership. Who knows.
"Some Paki paper says so" doesn't merit a whole lot of consideration from me.
FReegards!