Vinh KruczekChieftain with Grades 2s and 3s on modules, like stated in the post above.
All ships have the potential to escape the attacker, all CMDR's have the potential to win a Player interdiction.
The Engineers are available to all, spending more materials on upgrading it further likely would have been of benefit, plenty of modules to assist in keeping your FSD running, MRP's for instance, double bracing etc. Encounters with overwhelming odds can be difficult if not impossible to get away from. However, You should have seen them in SC, perhaps the encounter was completely unavoidable, perhaps it wasn't, but then that's why you don't fly without rebuy.
You should be expecting these things to happen and make sure you take the necessary precautions to avoid it if possible, Evade if necessary or fight back if you feel confident in your abilities and the situation.
There aren't many who win all the time and that's all part of it. I mean how much effort and how long does it take to make a Chieftains rebuy back Maybe 10 to 15 minutes max.