Author Rebecca Macfie, whose book Tragedy at Pike River Mine looked at why the West Coast disaster happened, said she was shocked by yesterday's court decision.
It sent a message that New Zealand was a place where a company without experience or sufficient capital could set up in a highly hazardous industry, lurch from mistake to mistake, defy basic health and safety laws and kill workers without consequence, Macfie said.
New Zealand should be "hanging its head in shame".
"Frankly, it's an embarrassment. This makes New Zealand a laughing stock; the fact that nobody is accountable at the end of the day.
"The only point of accountability in this whole bloody sad saga is a meaningless prosecution of a company that does not even exist any more in reality, because it's broke.
"No individuals who were the driving forces of this operation - and made pivotal decisions, and were in positions of responsibility to make decisions that could have averted this outcome - have been held to account."
Macfie said prosecutors had made an error in going after only chief executive Peter Whittall, and should have also gone after mine manager Doug White.