It depends how much you value people lifes ...
You
always have to value life at some arbitrary value. In this sort of scenario, it's potentially what it would cost you to rectify things at speed, and pay for a court case, and potential fine, in the case of a death, which could be a quite substantial amount of money.
(I think a fatality in a UK road incident is estimated to costs an average of around a million pounds, I would expect a higher figure for a fatality in this sort of case, largely because of it's relative unusualness).
Ultimately you always have to make some sort of judgement call on what is an adequate degree of safety. I think with this case most of us would consider that climbing that sort of structure with no sort of fall arresting mechanism whatsoever is beyond that point, but I presume the gentleman in question didn't.
As I recall, and it was some time ago I looked this up, he was (is?) an independent contractor, so presumably working for the company that manages the mast, and left as being responsible for his own safety. Now, strictly speaking in this sort of case, you can't say that it was entirely up to him to use an appropriate level of safety, and I'm pretty sure any court would find the management company at least partially liable in this case of a serious injury (or more likely fatality), regardless of the fact that the chap was working independently of their own management structures.