Incorrect notation after crashing Firefox

[Drakuun]

When my firefox is closed and reopened afterwards, it populates the same tabs again but does not load them yet.
Only when I click on the tab it starts to load the previous session on that tab.
However, the memory notation of tab data is still the same from before the crash even though it should be close to 0 at that point.
Might be more interesting to note 0bytes whenever a recovered tab has not been loaded again, since it hasn't taken up any notable memory.