[...probably because of the aforementioned poisoned article of clothing.]

That is probably true, for better or for worse. Of course, all things considered, I've been declaring a truce with all parties associated with the Holy Grail War for obvious reasons. Even though it technically doesn't apply in your case, I see no real reason not to extend the offer.

[...if it turns out that he completely wrecked the castle and the Einzbern master didn't get away then that should cover his bases...]