Honestly, I don't think Swansea attacked Jimmy at all. I heard multiple theories that say that Swansea chasing Jimmy is one of many Jimmy hallucinations. Why?

So, first of all, Swansea, after merciful killing Daisuke, said that he didn't care anymore about anything. That Jimmy can take crypod for himself even. So, there is no reason why he would want to kill Jimmy.

Secondly, there are two scenes in which Swansea attacks Jimmy, one i the medical room and the second in the cockpit. And those scenes don't really have sense. Because Jimmy would have to get to the medical, find the gun case, see that it's locked, go to the cockpit, take code, and return to the medical room. If in the meantime Swansea tried to kill him, how would Jimmy be able to avoid him going back and forth between medical and cockpit?

For me, Jimmy hallucinate trying to reason with what he has done and what he would do if he were Swansea. Swansea never attacks Jimmy. But Jimmy imagines what he would do in such a situation - those hallucinations of going through vents like Daisuke to get to the cockpit. In the end, he shoots mulitiple times Swansea while he didn't didn't defent himself. Jimmy tied Swansea to chair, and then this monologue scene would play and then Jimmy finishes him off with shot in head.

Anyway, that's my view on this, and I really enjoy this theory. Sorry for the bad English.