Does the employer have some sort of responsibility to fairly resolve this?
Yes. Although yelling or swearing at someone is not necessarily illegal, much of what you describe sounds in coworker's improper activity or behaviour and violence as defined in sections 4.24 and 4.27 of the BC Occupational Health and Safety Regulation. By failing to effectively address the matter, the employer is putting himself might land itself in proceedings pursuant to section 4.26. See also in this other answer the remark on section 2.8.
Try to secure as much evidence of the incidents as you can in case you need to file a complaint with the authorities or in court. For the same reason, make sure your interactions regarding this matter are in writing.
On the Workplace SE post you also mention "the manager asked me to write to her saying I thought our issue had been resolved". Do not do that. In fact, it is premature and quite incompetent of her to come up with that request.
The manager's apparent opinion that the coworker should not be with you is something you want to hear, but that [verbal] statement in and of itself solves absolutely nothing. The problem remains as long as there is a risk that you and the coworker will be scheduled together again. Complying with the manager's request despite your awareness that the problem persists will weaken your legal position if matters escalate.
Lastly, note the manager's request that you write it to her. This illustrates my point of why it is important that your interactions be in writing whenever possible. She is trying to cover herself by putting you in jeopardy.