I'm kind of with matthew in terms of it not being your fault but nonetheless a situation that could be anticipated and allowed for.
The driver should have seen you, should have given way, and as far as I could tell doesn't even really have the excuse of "a car won't fit through there so I'm good to go" as there *is* room for a car, especially once the Audi in front of you had begun to clear your lane.
It's too easy for someone just to follow the car in front, with the twin reasoning of "they're going, so there's obviously not a car coming" and "if there is a car coming, it'll have to slow down for them anyway, so I'll be fine if I just follow them close" (a car driver can, of course, believe at least six contradictory things in the space it takes them to clear a junction), so someone cutting across your bows is all too predictable.
I'd probably have been doing much the same speed: I might have been easing off a bit as the brown estate crossed my lane, and I'd probably have been covering the brakes (without standing) as I entered the junction. But once the brown estate has gone (as 14s ticks into 15s), you've got a clear lane ahead of you and a good view of the driver's-side windscreen of the black Focus. They didn't see (or didn't look) rather than not being able to see you.