Forget distant lighting see a high intensity light at close quarters and you will Damn well know its not floating in the air but attached to something hard!
Thankfully I've never been that close in the air, in bad viz or night. I have at sea, many times. An unexpected 'out of the blue' light is a "What the f*....?" moment. It is heart-stopping. Your jaw drops while your brain engages....with nothing but a light you don't know what you have on your hands. It's easy enough in an exam...red/green... but life isn't always like that. Until you get a bearing and assess the relative motion a light means nothing other than shock and horror.
Suppose he had seen the jib, lit, in the gloom, what colour would the light have *appeared* to be? The pilot obviously didn't expect it to be a crane - obviously or he wouldn't have been there!. Do you turn right, left, climb,...?
The AAIB will go through all this...but discussion is what forums are about, so we discuss...