That's a very inept employer/HR department.

https://www.dol.gov/whd/regs/compliance/whdfs28i.htm

"Time that an employee is not scheduled to report for work may not be counted as FMLA leave. If an employer temporarily stops business activity and employees are not expected to report for work for one or more weeks (e.g., a school that closes two weeks for the winter holiday, or a plant that closes for a week for repairs), the days the employer’s business activities have stopped do not count against the worker’s FMLA leave. "

Umm,....if they called him off due to THEIR reasons, they can't count that against his FMLA allotment....so no he would generally not have used 480 hours. He needs to document every time he took off due to HIS request vs theirs....

Usually I don't see great employee sided cases, but in this one unless you are explaining something incorrectly, he has a good case of FMLA retaliation.