A "fat finger" of only 10x is not that much of a fat finger and may not be detected for it's probably nothing out of the ordinary compared to the brokerage account's size. The fat finger in TFA, however, is a quite bigger fat finger: $444 bn instead of $58m.
That's 10 000x. That one is, indeed, a UI issue.
Also on fat fingers everyone will find this hilarious
That's not just an UI issue, the backend system responsible of executing the order should have caught the out of limits order.
Except that apparently they had such warnings for individual trades, but the bundle was implemented as "for(trade in bundle) transact(trade)". Which design has a certain appeal, standing on the shoulders of the peculiar handling of each trade, but with the terrible flaw that the bundle is never considered in its totality.