Ok, so they can't produce a picture of what it looked like out the window, so we can't know how red the X was or how runway like the taxiway seemed (wasn't it a smaller runway for a few years?)
But single controller was a factor, just not for the obvious reasons.
There's no way you can expect him to spot the misalignment in time, given the angle he has on the 28s.
But, for a relatively calm part of the day, what were all those a/c doing on the taxiway? The lead A/C had been waiting at the bar for thirty minutes.
When the ATCOs made the determination to go to a single controller, they did so based on the number of strips they had.I wonder if they took into account the evening closure of 28R? So, with one controller on ground and tower, Line Up And Wait goes into the break room. With all arrivals on 28R, the heavies have very few gaps to get out in, and no-LUAW means those gaps need to be bigger. So the heavies pile up on the taxiway, because the controllers didn't fully account for the impact of construction, as the AC bus lines up on them, for similar reasons.
ATC has changed their procedures since.