Whats his beef?
During heavy slow traffic its the norm these days for motorists to switch lanes as soon as they get a gap, I see it every day usually queuing for the Black Cat roundabout on the A1 so I purposely leave a decent gap in front to allow them in. This for some reason will irritate an occasional impatient driver behind. So what! None of us are going anywhere fast and you aint going to get there any quicker, just calm down, listen to the radio or have a fag if you smoke, a sweet if you dont, its so trivial and not worth getting upset about or upsetting someone else. So you may be a little late for work, is it really that important? Sometimes people just get stuck in the wrong lane or need to filter in, it happens to all of us.
Give him a wide birth and you may just manage to hit the old lady with the walking stick you didn't see in your excitment at seeing a nice car parked somewhere it shouldn't be ,
You couldn't pull over and wait, just a short while? Have a heart..