This is a tragic case, and I hope Mrs Sacoolas has a great deal of difficulty sleeping at night for the foreseeable future, but tragic cases don't always make for good legal decisions. Is it just me who thinks that the rhetoric here might be getting ahead of the law? The parents are entitled to a lot of leeway, of course, but it's not clear to me exactly who the Radd Seiger person is or what his role is, other than to chase publicity. He doesn't seem to be a lawyer and his Twitter profile looks frankly rather dodgy.
Over the last couple of years we have seen how vital it is that the judiciary be as independent as possible of political interference, and yet here we have litigants calling openly for government ministers to get involved and hoping that Biden will somehow overrule whatever the US courts might decide, if it ever gets that far. And I think we can all imagine what the tabloids will make of it. To the extent that "Dominic Raab has won this round", I feel like I'm actually behind him on this. He can have a quiet word by all means, tell Trump or Biden how great it would be if someone persuaded Mrs Sacoolas to get on a plane and surrender, but that surely has to be the end of it in political terms.
Tangentially, I also wonder how much evidence the police have to convict her of "causing death by dangerous driving". My understanding is that "dangerous" is the top of the shop, above "reckless", "inconsiderate", "careless", and "without due care and attention" [not all of those may be actual formal offences] and would normally be reserved for something like people having a race on the M1, not someone from a drive-on-the-right country who drove out of a side road and forgot to drive on the left-hand side. (Maybe she was tearing up the country lanes of Northamptonshire at 80mph under the influence of MDMA and with loud trance music blaring out, but it seems unlikely.) So if it did go to trial and her lawyers got the level of the driving offence reduced to "careless", and she ended up with a community order, we could look forward to extensive ranting from the laura norder crowd about lenient magistrates, PC gorn mad, string 'em up, etc etc. (FWIW, in the 1960s my mother's car was hit by someone who had just come back from a couple of months in France and was on the wrong side of the road. He got a small fine for careless driving, although of course my Mum's leg injuries --- this was back in the pre-seatbelt era --- don't begin to compare with the consequences here.)