Did the Airport company fail to maintain guidance lights to a gate so that an aircraft was waiting off a bay with engines running for the Engineer to get there and assist? Does the Airport company consider guidance unserviceability as a safety risk or are their staff not aware of downstream operational effects? Would the Airport company go broke if it considered guidance reliability as a safety concern and maintained accordingly?
The engineer still has to be at the bay whether the NIGS is working or not. Off schedule arrivals probably put more pressure on engineering. Perhaps the practice of airlines outsourcing to the lowest bidder/paying peanuts for engineering services or engineering companies delivering contracted services to multiple airlines with the bare minimum resources possible, thereby expecting or forcing one engineer to be in multiple places at once is more the issue.