Interesting also that in the INES pdf on that site, the requirement for INES4 is at least one death from radiation. Perhaps the declaration of INES level four was in error, or the requirement is not strict.
Another interesting link just found: http://en.wikipedia.org/wiki/List_of_civilian_nuclear_accide...
It looks to me like, on the wikipedia article at least, it's an "or" condition - probably the "Minor release of radioactive material unlikely to result in implementation of planned countermeasures other than local food controls." is what's triggering a level 4 event.
There is one confirmed death (a crane operator, but I didn't find any clear cause of death) and several injuries.
As he is already dead, it won't be radiation that killed him. Radiation poisoning needs days to do its ugly work. For the person to die within hours, the containment must have failed to allow sufficient radiation out. Since this has not happened, the person in question hasn't died from radiation.