recon laser designate targets that sustain damage

I just completed this bit, another instance of the description not really doing its job.

What I observed is that you need to use the laser designator in remote mode, so I would place it, remote control it, get a lock, then exit. From there it gets even weirder, it only counts if the vehicle is destroyed while designated, and single vehicles do nothing, I got 650 points every second vehicle.

So basically get on a roof (for safety from ground stuff) during something with choppas/jets (I used firestorm on a portal server), then jump through the above hoops to take out 8 aircraft and it's done.