How to interpret xerror of rpart (method="class") when losses are assigned?

[A-Pai]

How to interpret xerror of rpart (method="class") when losses are assigned

Strangely initial xerror is extremely small and it is 0.1000 (I see this is 1/loss of class 0), then xerror increases to 2.41, 2.77 and so on. Somehow xerror at the initial node is much much better than rel error!!