Hey,
What map were you on? I only ask because you mention repeatedly being killed but then saying you don't mind last flag rape...were the others neutral? :S I assume they were not capped by them or we wouldn't have this post.
Also, you're right; policing it would be a problem. Not only because of the admins, but also that it would be a huge change from the past where it has been fine. You'd also have to define rape; does main capping count? What about a heli pilot covering someone who is main capping?
However, while it is frustrating it is usually the "teams" fault when it happens. Most maps have an effective counter for the heli raping; your own teams heli's, jets, stationary weapons or ZSU and even players with M60's/LAW's or RPG/SA-7 but if these are not utilized then it is usually your own fault.
Personally, I don't think we need a rule for it as I don't see it happen often (E.G. Hastings used to be a guaranteed rape map but I've not seen it recently) or it is our own teams fault and it would be wrong to punish the opposing side because our team was at fault.
Regards,
SucceededKiller.