Another potential hole in the Swiss cheese is that I've seen reports that the C5 intersection had "stop bar" lights, but a NOTAM that was first posted on December 25, 2023 says they are out of service at multiple intersections including C5.
So it looks like we might have these holes line up:
- The Coast Guard crew mistakenly enters 34R without clearance.
- This is not detected by ATC.
- The stop-bar lights at C5 were inop, which would have shown a red "do not enter" signal if they were working.
- The incident was at night, and tests done as part of the investigation of the 1991 collision between a USAir 737 and a SkyWest Fairchild Metroliner at LAX showed that it's extremely difficult for a landing aircraft to see an aircraft on the runway at night because the nav lights on the aircraft just blend into all of the other lights. This was described in the Mayday episode on that accident (cued up below).