Calling TextField#getTextFormat(0, 0) on an empty TextField is perfectly valid and should return the default TextFormat. We throw an out-of-bounds error instead.
Couldn't verify such behavior. The following example throws an out-of-bounds error, even in the Flash Player: var tf = new TextField(); var f = tf.getTextFormat(0, 0);
Turns out the first sentence in comment 0 is a lie. The issue with the linked page is somewhere else.