Backpay for Probationary Firefighters

[FLAME5]

I have heard through the grapevine that a firefighter will be grievencing for back pay.
It seems he was hired with an intermediete firefighter certification but was not payed for this certification because of his probationary status, and the dept. has a collective barganing contract, which does not apply to probationary firefighters.
does this grievence hold water, and has anyother depts. had this problem?
Thanks,

[Engine5FF]

Our probies are members of the bargaining unit upon graduation from the fire academy and they are paid full pay from day one of reporting to the department. A probie, if working, is still a paid firefighter.