He would work more than the required hours for the grounds keeping job on match days, essentially he'd do 9 to 1 grounds keeping, 1 to 5 kit man, 5 - 11 grounds keeping. that's 10 hours on the job he's paid for (more than he's contracted to) and 5 hours of his own time. His only mistake is not being honest and disclosing this, there should have been no problem letting him do both.
If there was a problem, then why has Ehab been so negligent and allowed it to continue for years?
A simple warning was all that was needed, I'm sure he would have dropped the extra duties to keep his job, although anyone with any experience managing staff would have seen there was no harm in him doing both.