One sided is right
Whilst the USofA has ratified the treaty, the level of proof they need to grab anyone from the UK is non-existent whilst the UK must prove it has a case in a USofA court before any extradition, It is high-time our "ally" stopped treating us like the enemy and dealt with us on a fair basis.
What McKinnon is was wrong, no doubt on that, but he only managed it because in the 15-odd years the USofA has had to increase security since Clifford Stoll raised the alarm, they have done jack-shit.
We should, in this instance, try McKinnon in the UK, punish him here (if the cased is proven) and tell the USofA to shove it. Of course, maybe the USofA will just "extract" him covertly - they have form for not caring on the legalities of foreign countries or individual freedoms.