I have friends in forestry, and their industry routinely uses helicopters, despite the risk, for a much lower ROI. Below are some videos of a christmas tree farm and a remote logging operation. I can't imagine that what rocket lab is attempting will be anything short of 10-100x safer.
How about helicopters lifting things from the street to the roof of a skyscraper? With the spinning blades mere feet from giant windows with people on the other side?
Forestry is a fairly low profile blue collar industry that doesn't get much mind share among the white collar people who think they're experts in how every industrial facility should run. You have the luxury of actually being able to make decisions by the numbers.
When you go into space numbers unfortunately tend to have to take a back seat to optics.
Someone crashes a log truck and nobody cares. Someone crashes a helicopter doing "space stuff" and suddenly every jerk who feels slighted that you didn't divert enough resources from your primary task (space!) to pander to their issue (your team isn't divers enough, your facility isn't environmentally friendly enough, your company vehicles aren't all EVs, etc, etc) along the way is happy to tell the news reporter or the Youtube head how you "have a history of playing fast and loose" or whatever. And then all the vultures who want to be seen "doing something" descend...
In those farming/logging videos, the helicopter is picking up stationary objects and depositing them in a desired location. I have trouble imagining that catching a moving object would be less dangerous, except to the extent that the pilot's job is only to catch a single thing that day, not move dozens or hundreds of individual objects.
(Those loggers though in the second video seem like they're standing awfully close.)
Both are very hazardous under different risk models.
There's a concept in flying stuff that you always want to be "three mistakes high" (I think this is credited to Gene Gottschalk although I have no idea if he was the true origin - it's taken a life of its own in many communities). By that logic, the Christmas tree pilot is at a very sub-optimal altitude - 0.75+ mistakes high, but still high enough that they're unlikely to make it out in the event of a mistake or catastrophic failure.
The retrieval helicopter is presumably several mistakes higher and more likely to recover from simple mistakes or equipment failure, but runs the risk of being smacked by a flying object.
Neither are safe, but I think there are mitigating factors to the rocket collection that aren't present in the Christmas tree video. I think they're closer to even risk-wise. If I were a helicopter pilot, I'm not sure I would want either job!
Yes, the target will be a moving object, but its motion will be steady and predictable. The helicopter and booster will be the only two objects in the area, and capture should be slow and steady when viewed from the reference frame of the copter that has matched velocity. Aerial refuelings look crazy from the ground but easy but from the pilot's point of view.
https://www.youtube.com/watch?v=08K_aEajzNA
https://www.youtube.com/watch?v=kin7cxnyM1M