Well, then it is too late
since I am trying to modify the savegame AFTER I got the cutscene (and I don't have any savagames from before anymore).
On the other hand, every savegame, I think, MUST store the essential information that tells the game what events have been triggered or not somwhere. And IF KSE has access to this options,perhaps still something might be done.
Thanks for the reply - I have learnt a new thing - more than 2 savegames in such a huge RPG game won't hurt my HDD much.