What I'm about to say is not meant to offend anyone so please don't take offence, I'm sorry some of you lost a good friend.
But take a look at the weather report's from Bournmouth and the neibouring airports poor viss, Low cloud.
An eye witness report said the helicopter flew above him but he could not see it due to low cloud, He also said it was a cold misty night.
Not good weather for a VFR rated pilot to be flying in at night is it, I know I'm not the only here who thinks this.
Maybe the weather was OK till he was nearly at Bournmouth and then rapidly got worse which would have been very difficult for any of us to detect or know about in certain circumstance's.
But this does not change the fact's low viss, low cloud & a non instrument rated pilot at night is not a good combination, Leading to a spatial dis-orientation accident where sadly two people lost there live's.