Agreed. No-one is ever to 'blame' for incidents like this at any level....except boxing. This is why comparison to other dangerous sports is a fallacy.
But, most of the time, indeed, nobody is to blame. Boxing is weird in the sense that these tragedies happens most of the time in fights that are not particularly brutal.
People with manifestly thin skulls should be banned from boxing. The guy looked like his head was made out of paper.