No - I didn't use the wargear mod and still get the "Fatal Scar Error" in the "Wailing Doom" Mission. Seems to be a trainer issue.
Workaround:
Start DoW2 without Trainer.
Enter the "Wailing Doom" Mission.
Alt-Tab to Desktop.
Start Trainer.
Reenter Game.
Hit F1 and you're ready to go.
[Edited by Ratakresch, 3/8/2009 5:33:02 AM]
Still, a response from Cal or Pwiz regarding this issue would be nice