I think I get it now...
So UK law enforcement used a RIPA order to try to get him to decrypt his data, but weren't intending to prosecute him themselves. US law enforcement made an extradition request, but it wasn't backed with evidence to prove his guilt. As I understand it, the US constitution gives you a certain amount of protection against self-incrimination (i.e. pleading the fifth). The UK grants no such protection, hence RIPA. At the same time, the US isn't going to be troubled by any "fruit of the poisonous tree" concerns if the fact finding has been done for them in compliance with UK laws, even if the evidence gathering would have been illegal had they attempted it under US law.
It smells as if the law enforcement agencies in these two countries were trying to be cute by forcing him to self-incriminate in the more constitutionally lax UK, followed by extradition to the hugely more punitive regime in the US for the subsequent prosecution. That would be morally dubious, to say the least.
It's possible the US have enough to secure a conviction already - or maybe only enough to bully a plea bargain out of him. But it strikes me that given the unexplained delays in process the UK police probably have very little to go on. If the americans don't share their evidence with UK police pretty soon - and even then, only if that evidence is strong enough to carry a prosecution in an English court - then prosecution will be impossible in either jurisdiction.
I don't have a lot of sympathy for what Mr Love is alleged to have done, but if the police can't secure an honest conviction I won't have any problem seeing him walk away from this.