The period of the individual's contractual notice is the length of time for which JSA will be denied.
If you are saying that this friend is on 6 months notice of termination by his employer, then it is correct.
The reason is simple; part of the total payment negotiated under the Compromise Agreement is required to cover the contractual obligations of the employer - in the eyes of the JSA people, he doesn't become unemployed for another 6 months even though the contract is terminated.