Some very good points so far.
My surprise, and the reason I posted, was the scale of the response. What did 16 Police officers expect to do and why would they not leave until the aircraft had taken off again?
The call was made to D&D and I can fully understand why they would call in the emergency services. The fact that they were called makes the event serious enough to call for a full response.
The pilots in question (the crew were two shareholders of the microlight) had checked their instruments before crossing the Thames from Essex to Kent and noticed that the fuel pressure was below normal. They elected to land in a 50 acre grass field and check it out. The passenger decided to call D&D to let them know what they were doing. Out landing a microlight is no big deal, as PFLs are drummed into you in the training.
What follows is all in the wording and I'm sure that a call to Southend to let them know that they were making a precautionary landing would have had a less dramatic result.
As has been said, the response will largely depend on the info given by the PIC. "I am making a precautionary landing in a 50 acre grass field, to check my fuel pump", would generate a different response to "PAN, PAN, PAN we are making an emergency landing as we have fuel supply problems.
I have no criticism of the actions of D&D and the response time of the emergency services sounds admirable. The scale of the response may have been excessive, but as Kolibear said, recent events in Herts may well have affected this especially as it was two Police officers that were killed.
If I have any concerns, its that we are likely to see "Pilot crash lands only 2 miles from Benfleet housing estate" headlines in the weekend's papers. "Local resident, Sharon Bloggs, said 'They are always flying over here. I'm scared to let my Johnnie play in the back garden after this'"
Just a thought, isn't a PAN an distress situation not requiring immediate assistance?