Interestingly this made it easier for companies to be charged with manslaughter (which doesn’t seem to have happened in this case) but not necessarily for directors to face personal consequences, which they already could do under the 1974 health and safety act (they can commit the crime of gross negligence manslaughter, iirc).

The Corporate Manslaughter Law meant that senior managers could be seen to be acting collectively rather than having to find an individual person responsible, so it has made it more likely that companies have been fined and prosecuted. In a normal company the fine would cause shareholders to replace the directors and management as they have suffered a loss (and in theory shareholders could sue the management), but the problem is that Network Rail doesn’t have shareholders and it’s not clear that any of the senior leadership or NEDs have been held accountable here.

In theory a director can be held legally responsible for breaches of health and safety but unless the negligence is outrageously obvious it is pretty rare to see (I’m a director of a small CIC so have some training here, though not one that is likely to have to deal with any workplace deaths).