Crashed windows do not save back/forward history
As the title states. When Chrome crashes for whatever reason, generally Chrome will bring up the windows/tabs open at the time again. These pages all retain their forward/back history, but do not retain their Tabs Outliner tree. Tabs Outliners also saves its own version of the pages, which retain their tree but NOT their forward/back history.
Customer support service by UserEcho
So, mission Impossible, through there already some development (not released meantime) that allow to view the tree in any point in the past (and so, access the old tab urls). Of course it's not as userfriendly as back-forward buttons.