Ayup Paul ........ I'm on your side only difference is I wouldn't have even slowed.
The last time someone did that to me when fully laden ended up with a rather short back end to their vehicle, cars make a very good brake

and I had nowhere else to go, apart from into oncomming traffic and that wasn't an option I was going to take. Certain death for somone innocent as opposed to the possibility of death for an eejit .... the eejit drew the short straw and got 28tonnes of Volvo parked on his (empty) back seat. Luckily for him he only sustained shock, scratches, brown trousers(literally) and a hefty insurance bill.... the police saw the funny side and just laughed at him.
I gained out of the whole thing .... 5 hours overtime whilst the radiator was fixed at the roadside... and the 10 or so drops where backloaded onto another truck ;D
The only thing I would suggest is next time don't flash the lights, although that's what the highway code states its open to interpretation as it isn't the letter of the law. The Micra driver interperated your flash as letting him out as most peeps do. Heres the question ....... Had it been another truck would you have flashed? Probably not... had it been another truck he PROBABLY wouldnt have pulled out flash or not thats the difference in training.
I think if an accident had happened you might have been seen as 70% to blame mearly because you flashed and this would be seen as contributing. The argument against is that the Micra driver misjudged your signal and should have waited for you to slow signifcantly. Its the same as someone going through a green traffic light and being hit by a red light jumper. The guy passing through the green light could, in theory, be prosecuted as a green light only gives you the right of way .... it doesn't mean its safe to cross.
I think the moral of this is next time DON'T flash just back off, then you can't be accused of misleading anyone should anything untoward happen.
The Law is an ass when it comes to motoring ... so don't give it a chance to make an ass of you.
Keep on trucking
cheers
eno
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