21. A public officer or employee who is absent from work for a reason qualifying him for salary insurance is exempt, respecting the period for which he receives salary-insurance benefits, from contributions that would have been deducted from his salary had he not been absent from work.
In the case of reimbursement of contributions to employees, the contributions from which they were exempt shall be considered to have been actually paid. However, in cases where the salary-insurance plan so provides, the insurer must pay to the Commission an amount equal to the contributions that would have been paid and that amount shall be credited to the employee.
A contribution shall however be deducted from the amount received by an employee as salary during a period of absence compensated for out of accumulated sick-leave provided for by a collective agreement.