I'd swear that if it wasn't for people leaving before they get killed in RA, I'd have an extra 10k faction. Seriously, I'd like to see a penalty put in place for people that leave PvP missions early. Something as simple and (relatively) harmless as -100 faction would be plenty in my opinion. This means that every time someone denies their opponents 20 faction each (for a total of 80 in RA or TA), they have to match that faction plus some when they leave. If it's a one time thing, then it's no big deal. If it's chronic, then people will get punished for it.
This could benefit ABs and Fort Aspenwood as well, though this is less of a concern in these areas since there is a reward to the looser even if they stay.