At this time ArrowCreated is raised only when an arrow is drawn interactively.

You can detect that an arrow is re-created via undo/redo by handling the ActionUndone and ActionRedone events. Check if the type of a redone command is AddItemCmd, or if the type of an undone command is RemoveItemCmd. If that's true, the Item property of the command object holds a reference to the object that is added to the flowchart via undo/redo.

Deleting an arrow when undo is enabled does not actually delete the Arrow object, but merely removes it from the flowchart and nodes collections that refer to it. So when that's undone, you will get the exactly same object as the original, including any property changes you might have done in the ArrowCreated event.

Stoyan