As always, every rule brings a new loophole, it seems.
The drug-mule player will of course argue that he was defending himself, because if you had reached him, he would've been tased or restrained, and then the drugs would've been discovered, and he would've faced a large loss. In essence, this is still what would've occurred even if he had only been discovered in the church, at the exact point of transaction. It's 'cheaper' for the mule to kill you than it is to risk a prosecution.
Clearly though, for the cops, this is a nightmare. It means that every vehicle of any kind within walking distance of a drug dealer is a potential drugs carriage piloted by a trigger-happy murderer who will kill you as soon as look at you. Not nice.
If we implement a 'drug-mules cannot defend themselves' rule (and/or with an 'unless they are within x feet of the dealer' caveat), then of course, we'll hear nothing but whines from the drug-mules who will now get nicked each time they do the long walk to the dealer, and we will be basically back to square one, except the cops will be happy and the civs won't be.
If we implement some kind of 'protocol' as to how a drug-mule is meant to respond when challenged, next to his drug-filled wagon or chopper, then the end-result is still that most likely, the drug-mule will get busted, and lose a lot of cash, and I'll hear nothing but whines about that too.
I think a modicum of common-sense is called for here.
If a cop sees a chopper (or gets reports of one) landing nearby a large town, the assumption must be that the pilot or passengers are 'up to no good'. Most likely, they'll be dealing, and armed. That surely has to be the presumption? Why else would they be breaking the no-fly law, or risking drawing attention? There's clearly been some kind of risk vs reward calculation going on in the mind of the pilot to make such an obvious 'show-out' worth their while... so it most likely is going to be drugs, isn't it?
So, given that, surely the rule *must* be 'approach with extreme caution'. If you stroll up in a cop wagon with the blues-and-twos running, and a druggy sees you, he knows what's coming. His capture and prosecution. So he's going to switch to defend mode, isn't he? He's not going to hide away and let you crush his chopper and confiscate all his drugs, without a fight, is he? We can hardly blame him - for him, the 'roleplay' is already well-established... it's the cop who is out of the picture, and doesn't know (yet)... but that's not the druggy's fault, is it?
Similarly, if cops approach a situation like this on their own, they are likely doomed. Such vehicles as HEMTTs or helicopters in or near the edges of town simply scream 'drug-run' to me, so waltzing up and saying "hello, hello, hello, what's going on here?" is likely to NOT get a "golly gee copper, you've got me bang to rights and no mistake, it's a fair cop, I'll come quietly" sort of 1950s black-and-white movie response.
Nope. Instead, the cops should immediately switch into an observation mode. Have one cop (or more) tail the suspect and confirm that he has left the vehicle and see if he heads to the drug dealer (watching out for indirect or double-back routes). Have another cop (or two) check the area around the vehicle thoroughly. If the vehicle is clear of suspects, move in to search it. Don't crush it immediately, but search it and remove the contraband IF SAFE TO DO SO. Identify the owner. Work with the tailing team to confirm the description of the person walking to the dealer matches the ID on file for the vehicle owner (i.e. nametag match, in OOC terms, but RPed this way is fine). Then, unobserved, see if you can confirm whether he has a weapon out, or on his back. If he has, you may have to tase him very quickly after a verbal warning, or perhaps even without one. Either way, you approach him from behind. You may even prefer to just leap out from behind a wall and restrain him instantly. Those are all fair game, in my view. In essence, you minimise the opportunity for him to spot you and kill you (because he certainly will, given half a chance).
He may cry 'you didn't say anything, you didn't roleplay', but in that case, my response would be 'Bollocks. You marched into Kavala with a haversack full of drugs, and were seen, identified and followed. RP is established.' If a player is prepared to take that risk, but not take the chance of being caught, he's mad. And certainly, as we've seen, if he has the chance NOT to be caught, he'll take it, even if it means killing the cop.
It's a bit like real life in this respect, really. I've seen New York cops routinely unclip their holster and cover their weapon when dealing with a TRAFFIC STOP. And only last week, in my sleepy, normally-quiet home city of Bath, a whole HOUSE was deliberately burned down by a couple of guys who'd turned it into cannabis factory. We're not sure whether they were rumbled by cops and were destroying evidence, or whether they were a rival gang putting a stop to any competition on their patch, but either way, the poor bastards who lived in the adjacent terraced house next door, and who lost EVERYTHING, probably don't really care about the reasons. They're just lucky to be alive.
Cops need to be cautious. If there is the slightest chance that drugs are involved, then it probably follows that a lot of money is at stake, hence there will likely be weapons about, and people who'll use them to stop themselves getting caught. Be on your guard. The days of Dixon of Dock Green and Z-Cars are long gone.