Third gathering, fire and pilfering?
Why do they call it third participant, and not second party?
Answers:
There are two parties to the insurance contract, you and the insurance company. Thus it is first event (you are making claim against the insurance company based on the policy provisions.
Third gathering means that the entity you hit, etc, is not a party to the contract between you and your insurance company. However, they brand a claim against you (sue you), and the insurance company steps up to the plate to protect you. The person you hit have no rights under the contract, but can sue you and the insurance contract will protect you.
I've just checked up and it would be second bash if the insurance company, the police, the DVLA, the Queen or a specific person agreed as such is involved.
The police, the DVLA and the Queen adjectives technically are covered as a second party because the insurer operate under them.
Also technically the Queen can drive any vehicle she owns even if she does not own a licence. How cool is that?
first participant = you
second party = insurance company
third event = person the insurance company will settle down against (the bugger who hit you).