STC NPE using DGM collect on Iterator

@groovy.transform.TypeChecked
def m() {
    List<String> list = ['foo', 'bar', 'baz']
    list.iterator().collect { it.startsWith('ba') } == [false, true, true]
}

m()

BUG! exception in phase 'instruction selection' in source unit 'TestScript.groovy' unexpected NullpointerException