Ferris from what I gather you must be a controller in the UAE, is that approach DXB or AUH?
To answere your question what is happening is the following. When an Airbus is in the hold outbound and you issue a clearance "go direct to the VOR, cleared for the full approach" for example the pilot has to intervene and do either a direct to function or what we call an "immediate exit". In this case the aircraft will turn direct to the point requested. What I suspect happens sometimes is that if you clear an aircraft which is outbound for the approach, then the guys just let it stay in the hold until it turns inbound, then presses the immediate exit. There is no problem at all if while in the hold you issue a radar heading followed by a direct to a point either.
Hope that helps, take care and keep us safe.
Snails