Generally an everyday occurrence, not worth getting that angry about. Looked like the d'n'b driver wanted to take an opportunity to make a little progress (i.e., about 3 metres) but is massively angry that it didn't work out. Any "merge in turn" design results in this.
Fogging again - R15 RCR
Sick of getting fog light blinded by this idiot. Some more info - Outside Clopton Farm on the B1042 heading west between Tadlow and Croydon, South Cambs - 08.40am
Good old Britain. We're all best of friends here...