When the missile is ready to launch and you select your target, it will immediately launch with no delay.
In a game like this
https://zero-k.info/Battles/Detail/1872092I accidentally nuke my own base, because I accidentally selected my nuke and force fired, with NO chance of stopping the missile.
Just an idea, of when you want to launch the missile, there should be a little 5 second timer before it launches, so that you can stop an accidental launch, and prevent situations like this.
And before people say to change selection setting for nuke or something else, it won't completely stop it, as you can still accidentally select the nuke with CTRL + A or something else(forgot the keys)