This is a matter of being sensible and reasonable. If the total leakage is enough to cause nuisance tripping, it's possibly enough to cause injury. He's planning to be using the circuit for handheld devices etc where the user might be the only earth path, so rather than pretending the problem doesn't exist, a high-integrity earth is probably warranted. Correctly specced RCDs / RCBOs will not suffer from nuisance tripping, so don't put people deliberately at greater risk by omitting them.
The exemption is to deal with specific situations where the socket is only ever going to be used for a specified piece of equipment, that might need to be taken down for service or fitted after wiring is completed etc. so needs a plug, as per the roller shutter mentioned. Permanently installed networking hardware is another, where a socket is needed because the power supply is a plug-in wall-wart type, but the equipment is permanent. No-one is going to plug a vacuum cleaner with a gashed flex or damaged Game Boy power adaptor into the dedicated socket above the office ceiling in place of the network switch. A socket on the wall in a house is different - there is no valid reason for exemption.