The crash arrester was missing when the Tesla crashed there, which is also part of the reason it was a fatal accident.
I do think that it had already stopped at least one, maybe multiple crashes since it has been last replaced.
The discussion here though is about visibility, and the attenuator would have been quite obvious there.
Page 2 (which is actually the 22nd page of the pdf) shows an image of the pre-crash state of the attenuator. It is present, but non-operational due to a previous crash. While that crash affected it's usefulness, it's visibility is only marginally reduced.