Re: incompetence via laziness
Given the level of automation, I'd suggest that the system would be able to get the termination date from the email, or that a termination date would entered by a program/HR person, the email would be generated, and the termination process was set to start on the entered date.
In this case, the unfortunate victim was a contractor who was on a time-limited contract with an acquired company, so the termination email was generated automatically, which means that there was no human involved.
The automation actually show that the company had some good security policy.
The problem was that the system didn't allow for human error, so it wasn't able to be interrupted and reversed. Based on the BBC article, another problem may have been caused by the company failing to be proactive and communicating their error to other employees and contractors to make it clear that the company itself had screwed up and not the employee/contractor.
Not the first time that company procedures failed to consider human impact.