Sandy?
My chats with the other 849 boys who were there that night led me to believe the air was carrying a lot of sand that night. In those conditions (like being in cloud) it don't matter none if you're on anti-cols/HISLs or whatever, the reflection from the sand caused by the lower light is at best distracting, at worst blinding - so you're likely to turn 'em off. Hence the possibility of bumping into your oppo increases a lot. I'd have done the same I hasten to add.
At night I routinely turn off my lower strobe (especially on NVG) if it's wet/cloudy, as the risk/benefit of distraction/collision vs easier flying usually weighs up in favour of selecting "OFF".
You can argue about which lighting set-up is better/airworthy until the cows come home to roost, but the simple fact is, most of us in that position would have had a light off. As eluded to in earlier posts, this was one of those tragic accidents - but no more than that. I'm certain the RN have examined how to launch/recover cabs with slightly more coordination (although I'm not aware of the actual outcome there) but the bottom line is that looking at lighting is a hiding to nothing here.
SB