Why was it an error to jail someone for arson? Arson is a crime. As I said, women were given the vote in 1918, as their value and contribution to the war effort spoke volumes, rather than acts of 'terrorism'.
Switzerland didn't give women the vote until 1971, but I don't remember wholesale law breaking there.
There is precedent for these pardons though. In 2006, 306 soldiers excecuted in WW1 were pardoned for military crimes including desertion, and cowardice, both of which are still crimes in the Armed Forces.
Obviously, unlike gay men pardoned for homosexuality, these soldiers were dead, but, there is documentary proof that it meant an awful lot to their families.