There have been a spate of articles about the death of Rosa King in the last day or so. I am not sure why since they seem to refer to the July 12th coroner's report already reported upon. Nonetheless they are worth reading. Two points are made that the Guardian articles linked above either do not make or do not dwell on.
The first is that between the time of Rosa King entering the enclosure and the time of the discovery of her body the enclosure was unsecured and the tiger could have exited and potentially attacked members of the public.
According to the report airlock-style gates have now been installed that would in theory prevent any part of the enclosure ever being open to the outside.
The second is that at the time of the tragedy in 2017 Hamerton did not have firearms (guns) on site. When the report was released in July 2019 Hamerton still did not have firearms onsite, although two staff members do now hold firearms licenses. It is not reported what the situation is in December 2019.
Here are two of a number of articles:
Coroner warned of future deaths at zoo if measures aren't taken
'Only by chance' tiger didn't attack zoo visitors after mauling keeper to death
(Be aware that the second article makes at least one factual error: it refers to Rosa King caring for a tiger cub whereas in the report it is a serval kitten.)