Zardari spent about 12 years in jail between 2 NS terms in govt and Mushrraf. Now, life imprisonment in Pakistan is 14 years. So, 12 years is pretty long time to keep someone in jail waiting for trial & when nothing was proved against him he was let go....and of course Mushrraf gave him gift of NRO...
Though he suffered under the NS regime, the jail time that Zardari served under Musharraf was also in those A class jails, where they have air conditioning, freedom to goto places etc... Big waste of money, if they couldn't convict him of anything in Pakistan, why did they waste so much money on keeping him jailed, if all they did in the end was let him go free after so many years.