On the facts as presented – no it won’t succeed. The employment relationship terminated on the contractual date of retrenchment. The CEO can’t unilaterally vary the contract by extending it. The employee was still employed on the date on which the VSP became due and payable. So the employer would be contractually obliged to pay it.
However, the wording of the provision in the retrenchment contract apparently reserved the employer’s right to discipline employees for misconduct committed during the notice period. If so, this may produce a different conclusion.
The provision may have made payment of the VSP conditional on the employee refraining from acts of misconduct during the notice period. If so, the finding of guilt after the contractual termination date could be still be valid. This is because the misconduct was committed during the notice period – precisely as the contract anticipated.
This would entitle the employer to withhold payment of the VSP. The entitlement would derive, not from the employment contract, but from the retrenchment agreement. For this reason, there would be no need for the CEO to “extend the employment relationship” beyond the date of retrenchment.
He for the employer could simply enforce the provision in the retrenchment agreement to the effect that payment of the VSP is conditional on the employee refraining from acts of misconduct during the notice period.