synchronize2dIntersectionViews() could crash in two ways: when the view's ownerCase() is null, and when the collection has no Rim3dView ancestor at all (e.g. mid-destruction after detaching from the PDM tree, where firstAncestorOrThisOfTypeAsserted<Rim3dView>() returns null since CAF_ASSERT is compiled out in release). Both cases are now guarded.
