There are seven freighters, at least four must be stoppped. The Variables Jump and Destroy are counting if one of them gets killed or jumps out.
The fail events are: Jump = 4, Jump 3 and Destr = 1, Jump 2 and Destr = 2, Jump 1 and Destr = 3, Destr = 4. Every time one of the 3 things happens to a ship (disabled, killed, jumped), the corresponding variable gets +1.
Yes the event fires at the start, you find the convoy and have to disable at least 4 of them before they jump.
I'm wondering because the event turns true (blue) once 4 are disabled. So it's not a mistake inside the counting itself... It just doesn't turn red...