I think this topic comes up every few weeks. Maybe it should be "stuck". Here's the deal:
The ending you get is dependent upon Hawk's and Panther's morale at the time of the Assembly confrontation. Your choices in the Assembly serve only to provide a chance to lose the game, even if you've done everything right up until then; they do NOT affect the "winning ending" (assuming you make it through and best Tolwyn). Now then, back to Hawk and Panther.
Every choice you make that affects their morale has a play as to what ending you get, by raising or lowering their individual morale. However, there are three that are most important, because they pit the two against each other directly, and your choice raises one and lowers the other. Those choices are:
Do you protect the civilians in Circe (Panther) or get the weapons in Speradon (Hawk)?
Do you state that "There's always hope?" (Panther) or "We die trying..." (Hawk)?
Do you try to fly through the Ella system (Panther) or flashpak the Ella superbase (Hawk)?
It is quite possible to choose two of these in support of one character, and still get the other ending, depending on your other choices throughout the game. It is, however, nigh impossible to choose all three one way, and not get that corresponding ending.
Contrary to a popular belief, the choice at Ella is not the one and only choice which determines the outcome. It holds no more weight than the other two "core" choices.
Now you know.