Yes, it's possibly true that failure modes could be more extreme.

Practically, in the discussed system the pumps themselves have built-in maximum boluses so the control-loop is limited in how badly it can fuck up. Of course, you have to trust the pump firmware...

That said, I've done some pretty stupid shit. Like the time I injected a huge bolus of novorapid, thinking I was doing my Lantus shot. Ugh.