Think about it. These guys have just been hit by a double-whammy. First an earthquake that has to be close to what the plant was designed to withstand, if not beyond. And then a tsunami that takes their station to blackout conditions. I'm confident they have emergency procedures to deal with this situation - not this specific chain of events, but their symptoms. Symptom based emergency procedures have been around for many years. The approach was developed by the industry as a lesson learned from the Three Mile Island accident in 1979.
In a symptom based approach, a limited number of key parameters are monitored and controlled, without the need to determine the exact details of the event. For example, reactor level and containment pressure are two key parameters. Falling reactor level could result in inadequate reactor fuel cooling, so a prioritized list of means to add cooling water to the reactor are developed and incorporated into emergency procedures. Typically, the last item on the list is to change the plant piping alignment such that the fire suppression system can be used (via connections outside the reactor) to pump 'raw' water (in this case sea water) directly into the reactor. Given the station blackout conditions, this action would be expected if cooling water inventory were required to maintain reactor water level.
Similarly, containment pressure can not be permitted to get too high. So periodic, planned and controlled pressure releases are implemented to manager that parameter. This could involve some radiation release, so part of the planning involves the precautionary evacuation of local residents.
But my main point is that the Emergency Response team is obviously VERY busy dealing with the immediate situation. And while the general public is desperate for information - which they rightly deserve. There are others who have a greater need for the information and communication channels to manage their responsibilities. These include the first-line decision makers at the reactor site, regulatory authorities, local and national emergency management agencies, local and national government agencies, the plant designer, and international support agencies. Information must be verified and any conflicts resolved quickly to permit decision makers to take timely action to protect the public to the best of their ability. These communicators are among the most busy people trying to manage the situation and the importance of them getting it right can not be overstated.
Those in the best position to communicate with the public (government offices for example) are also furthest from the detailed information flowing within the plant and have to manage many other, non-nuclear relief and recovery operations in the aftermath of the earthquake. Therefore, their statements tend to be quite brief, never speculative, and typically lack details of 'what happened'. The 'what happened' will be determined later - the plant operators are not concerned about determining this as a priority now. They are busy managing the symptoms and critical safety parameters, not being driven to describe events of the past.