As long as we approach the event with the assumption that these two pilots didn't do it on purpose ( I think we can all agree that is the case), and keep in mind that there have been many incidents of experienced and competent pilots landing, attempting to land, taking off, and attempting to take off on taxiways, then we must accept that the human brain is susceptible to creating the wrong patterns ( as mentioned by humble pax) if the stimulus presented is incomplete or differs from that expected.
What we do next is important, do we change the stimulus presented ( difficult in the real world but synthetic vision etc may help), or do we work on expectations? ( ATC required to transmit phrase " Runway 28R is unlit" on first contact) Or both?
If closely parallel runways had a lit orange circle or cross as part of the 1000ft markers and on a visual it was a requirement to have it in site and have a landing clearance to touch down, would that make a difference? On a PRM it wouldn't matter as the guidance is there.
Thinking out loud.