Denial of free speech
Three introductory points.
Firstly, my wife's family were, until the late 1930s, German jews. By the mid-1940s, a few of them had become British jews but most of them had become smoke and ashes in Poland.
Secondly, I suspect that the Germans have strict laws against 'holocaust denial' because, as the nation whose genocidal policies resulted in the systematised deliberate cold-blooded murder of over 11 milion people (including 6 million jews) they are guilty as hell; they feel guilty as hell; and they are are terrified they might do it again.
Third, the holocaust (in which I include jews, roma gypsies, Polish civilians and PoWs, Russian prisoners, homosexuals, the mentally disabled et al) is undeniable, not least because the ever-efficient and bureaucratic Germans kept such extensive records and also because thousands of allied servicemen and diplomats saw the camps and the victims.
So to "Dr" Toben. If he and other scum like him (the rebartive Irvine for example) want to preach holocaust denial, they do little real harm and they discredit themselves as "academics". They can re-interpret, bend or fabricate evidence til their dying day but the vast majority of people will believe the facts not their fiction. Holocausts deniers may be vile but that is insufficient reason to silence them IMO.
In some countries it is illegal to deny the holocaust. But what precisely is Toben accused of? In your story, it is variously "holocaust denial", "publishing anti-Semitic content on his website", and "downplay(ing) the extent of the Nazi's mass extermination of Jewish people". Which? All three? Does the last constitute the first?
More to the point, what precisely was charged on the extradition request?
I do not think the UK can refuse an extradition request solely on the grounds that Toben has not committed a crime in the UK (or appears not to have). However, it appears he is not a UK citizen nor is he resident here. Furthermore, an underlying principle should prevail: in Germany free speech is evidently even less acceptable than here in New Lamer Britain.
I do not think Toben should be extradicted simply to help Germans appease their (rightly) guilty conscience.
Our horror at what happened in Europe in the 40s would better be served by never forgetting who perpetrated it rather than colluding with the guilty in persecuting a few ranting nutters.
As a footnote, I too detect a decidely anti-semitic tone to some of the comments above.