US jailed Fai on the simple charge of only lobbying for legislation in support of Kashimr's freedom, an old man now, who has been doing this for many decades suddenly US prosecutors found it illegal and nabbed him a person doing something good, and in front of everybody.
Dr. Afridi on the other hand collaborated on a CIA mission, that has been termed unlawful even by Amnesty International since it violated Pakistani airspace and despite having the chance to capture OBL alive they shot him. Causing actual violence, several deaths, explosions, mobilization of SSG, Pak Air force, and US Navy seals lied to Pakistan ATCs and Dr. Afridi also lied to various residents of Abottabad that he is giving them vaccines on behalf of the government whereas he was giving them god knows what and to top it all off when he knew where OBL was, he didn't tell Pak authorities he told CIA.
All in all, the hypocrisy is amazing from the US side. It jailed an old man with such venom for being a foreign lobbyist who was not registered, we however are jailing someone for the high crime of Treason, treason of collaborating with a foreign intelligence agency.