The mission flow is that the Indart is only suppose to survive long enough to provide enough fuel for one jump. However, there just isn't enough firepower aimed at the Indart to keep a skilled player from saving it and breaking the mission. Hull integrity and ammo will be stretched thin if you try and shoot down all the raiders, but it is entirely possible to save the Indart without cheats. I have to purposely let some raiders through to beat that mission in a timely manner.
I think the solution here would be to have wings of Cylon Heavy Raiders jump in right next to the Indart - something I've seen in various FS campaigns to ensure that a light starship that is supposed to die does in fact die. And if it's still not dead, use a SEXP to kill it.
The HLP modding community is normally good at taking into account alternative sets of events like this, so this was a surprising problem for me.