Assuming that they didn’t do it on purpose, it will be interesting to read what sent them down that route.
I suspect following the wrong markings could be high up the list. How many experienced pilots can put their hands on their hearts and say they’ve never started off down the wrong line, or even just changed their minds as to what appeared to be the correct option before committing to it? At the same time, it does seem to be a rather prominent obstacle but it might have looked different from cockpit level - lost in visual clutter, maybe?