It seems there is a measure of truth in the assumption a freeman could be exempt from military service.

BBC: City limits - how free is a freeman?

He wants to end the special treatment enjoyed by ultra-orthodox Jews, who are exempt from military service and who often choose to devote their lives to studying scripture on welfare rather than working and paying tax.

BBC: Netanyahu dealt weak hand by voters

The Supreme Court has ruled that the haredim must no longer be exempt from military or national service.

ECONOMIST: Israel needs to solve a problem with its most religious Jews