The one colleague I know who operated a flight back negotiated a very favourable deal for the rest of his roster as they were in a tight spot. Win/win.
Come the next month the good deed will be totally forgotten and there will be 92 hours of fun and excitement.
Let them be in a tight spot as it's their problem. If we were rostered sensibly and treated with a degree of respect by management, perhaps you would not be put in a position of being asked to operate back, due to a colleague who has gone sick down route.
You don't need to fill in the offbase notification to be asked to operate from an outstation anyway. TRIPS can be checked to show who has flown to the outstation concerned and not returned to Dubai. This is another reason why it can be beneficial to use other airlines for staff travel. You don't need any of your credentials as copies will be sent to the outstation to enable you to operate back.
The easiest thing to do is say you enjoyed a couple of glasses of red in the last hour or so and therefore can't operate until the required 12 hours has elapsed.