Forum Rider Down and/or notification of minor incidents

It's not filtering as I read it, she was flashed and didn't bother to check for traffic in the second lane.

Yep, even if the lorry flashed, she should be more careful;

Yup eyebrows. Sounds like you're fully in the right and she's a fool. As others have said, totally her responsibility for not checking for all oncoming traffic.
Yes, absolutely.

But the courts consistently apply liability across both parties in this instance, so that just might be worth keeping in mind should there be any challenge as to whom should cough up for any costs or damages.

Leeson v Bevis & Tolchard (1972)

The key point to remember about cases where a vehicle is allowed to turn across the carriageway by another vehicle, is that 'a motorist who flashes his lights, or gives some other signal to another motorist who is seeking to execute a maneuver, is merely saying ''I shall wait here until you have finished''; he is not saying ''It is safe to proceed"'.

Junctions are a naturally dangerous place for cyclists. The road traffic rules in and around junctions are straightforward and covered in the Highway Code. Much of the case law on junctions tends to revolve around misleading signals.

Misleading signal cases are relevant, and it's helpful to have an idea of how the courts apportion liability in such cases.

Of more interest may be the case law on filtering. Filtering – or lane splitting – is legal in the UK, and other motorists are warned of the possibility of filtering vehicles in the Highway Code, where Rule 151 says: "In slow-moving traffic you should 'be aware of cyclists and motorcyclists who may be passing on either side."

Despite the warning and legality of filtering, liability in accidents involving filtering vehicles tend to result in the sort of split liability decisions highlighted in the above article.
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