As others mentioned, it was not an automatic attack; humans were in the loop. Even with humans in the loop. I think it is fair to say that sensitivity was set very high; the only difference is that it is much harder to control high sensitive humans are.

Regardless of that, keep in mind that this happened hours after Iran bombed military bases of the country that runs the worlds largest airforce, and days after said military bombed their general.

Under these circumstances, it is entirely reasonable, normal, and expected that Iran would set their sensitivities to very high. It is also expected that doing so greatly increases the risk of an accident, which is why countries only do it when they have extra reason to suspect an attack is likely. The downside of a false negative is not 0. It is that who-knows-what gets bombed, and who-knows-how-many people die, causing who-knows-how-much damage to the country and its ability to defend itself in the future.

This situation is also how wars start. We got lucky that the mistake seems to be such that the big players (eg. the US) are willing to let this go as an accident and let hostilities return to their normal simmer.