Southsun Cove event - no award
I don’t think there are any events, aside from collection-focused ones in which you can get credit without also getting credit for at least one kill. Further, for any event, not all foes in the area count as “part of the event” — usually, it doesn’t matter because you kill both non-event and event foes along the way.
So in this case, I’d be willing to be that you are killing non-event foes and you’d get credit if you managed to tag/get-kill-credit for at least one event foe before you burn out the last nest.
I’d argue that leaves the event “working as intended,” since it’s not meant to be completed solo (YOLO or otherwise). Sure, the description is a tad misleading, but only if we’re unaware of the general requirement to kill stuff during events.
That said, it’s worth a bug report — ANet might (or might not) be adjusting the event someday for whatever reasons and this would be easy to address at the same time.
Anything I end up having to kill comes from the mass of karka that spawn inside the camp, so the only way I’d get non-event karka on a repeated basis would be that some of the karka that spawn at the event’s beginning aren’t considered relevant to the event. If so, it’s quite a screwy design decision.
I suppose I can torch a few extra karka along the way in the future and see if it makes any consistent difference.