Nothing wrong with departing in RED if the weather at destination is suitable. If that means that an improvement is forecast by the arrival time, then so long as fuel for a suitable alternate is available, there is no problem. That's equally true for an A330 as for a Hawk; the difference lies in the definitions of required weather at the point of departure, point of arrival and alternate aerodrome.
Presumably the rum, bum and baccy mob have rules under which their alleged 'no diversion' policy is acceptable. I doubt whether it would be so in all weather conditions.