Larry Silverstein, the leaseholder of New York’s toppled Twin Towers, has begun his appeal against a court decision that the September 11 disaster was one incident, rather than two separate incidents.

It’s a long and complex story. Basically, Mr Silverstein had a policy that had not been completed. Under the Willis-supplied policy documents, the disaster could only be seen as one event, with Mr Silverstein’s maximum payout per event fixed at $5.2 billion.  Under another associated form devised by Travelers Property Casualty, the attack/s could be seen as two events. This is because the word “occurrence” is not defined.

With $5.2 billion extra at stake, it’s a case that is attracting a lot of attention. Lead insurer (there are about 20 in total) Swiss Re says the Travelers form is an “elaborate hoax” by Mr Silverstein to drag the case out.

The Circuit Court of Appeals will now sort out which form was in force. The case will then return to the mainstream court system for what is expected to be further interminable argument.