Series 9 Rumours & Speculation

[WhiteSwan]

Quite frankly I can't think of any situation, which would justify a suicide in Lucas' case.
If he's on the run and finally cornered by MI5 then the honourable choice would be not to kill any more people and not to kill himself but to surrender and face the consequences of his actions. Of course this would be extremely hard for him to do, given his 8 years imprisonment in Russia, but I would have a lot of respect for him if he did.
The same is true for the situation when it's just Harry on his own facing Lucas. I'm sure Harry doesn't want or need to kill him - as I understood it he gave the order to find Lucas and to bring him in at any cost, meaning dead or alive, but he didn't give the order to kill him at any cost. So Lucas doesn't have to take his own life in order to save Harry the trouble killing him. Again, he could just surrender.
And he certainly doesn't have to kill himself to save other people from Vaughn (or the people behind him). He blackmails Lucas to get information, but if Lucas decides just not to give that information or if he's no longer able to get the information, then the only person in trouble is Lucas. I can't see how there could be a threat to other people, which would be solved by Lucas taking his own life.
That's why for me personally a suicide could never be justified and it would be a painfully disgraceful and cowardly ending. It would mean that Lucas apparently did something extremely bad and then didn't have the courage to face the consequences.
But who knows, the writers may still surprise us with an intelligent ending!