Some errors are ignored, is that ok?

[ylsGit]

I've noticed that there is some ERROR being ignored here

func (node *Node) traverseInRange(tree *ImmutableTree, start, end []byte, ascending bool, inclusive bool, post bool, cb func(*Node) bool) bool {
	stop := false
	t := node.newTraversal(tree, start, end, ascending, inclusive, post)
	// TODO: figure out how to handle these errors
	for node2, err := t.next(); node2 != nil && err == nil; node2, err = t.next() {
		stop = cb(node2)
		if stop {
			return stop
		}
	}
	return stop
}

Is it normal that some errors from GetNode, especially fmt.Errorf("Value missing for key %v corresponding to nodeKey %x", nk, nodeKey) will not be processed? Is it expected?