Safety

Hi everybody..
I've got to analuse this case in one of my safety assignments..and I'm wondering if anyone would have an idea of what I may add in my analysis..
the case is:
In a normal operation in a batch reactor, the pressure drops as the reaction (of a flammable liquid) completes; an interlock has thus been installed to prevent the product being released to the product tank until the pressure drops below 0.3 barg. The reactor is washed out with water between batches.
One day the reaction fails and it is decided to vent the contents to atmosphere. Someone has forgotton to disarm the acutator on the discharge vlave,however, and this lifts unexpectedly when the pressure drops.
Analyse the situation to suggest what hazards this situation presents. how might u improve it?

Thanks!