"Immediately after the Paris meetings, things began to happen. On Oct. 21, Iran publicly shifted its position in the negotiations with the Carter Administration, disclaiming any further interest in receiving military equipment. From my position at the N.S.C., I learned that Cyrus Hashemi and another Iranian arms dealer secretly had reported to State Department officials that Iran had decided to hold the hostages until after the elections.

Between Oct. 21 and Oct. 23, Israel sent a planeload of F-4 fighter aircraft tires to Iran in contravention of the U.S. boycott and without informing Washington. Cyrus Hashemi, using his own contacts began privately organizing military shipments to Iran. On Oct. 22, the hostages were suddenly dispersed to different locations. And a series of delaying tactics in late October by the Iranian Parliament stymied all attempts by the Carter Administration to act on the hostage question until only hours before Election Day.

After the election, the lame-duck Carter Administration resumed hostage negotiations through Algerian intermediaries, but the talks stalled. On Jan. 15, Iran did an about-face, offering a series of startling concessions that reignited the talks and resulted in a final agreement in the last few hours of Jimmy Carter's Presidency. The hostages were released on Jan. 21, 1981, minutes after Ronald Reagan was sworn in as President. " (extract from *)

[Can a Goverment mislead?
It can, it has and it is doing so right now in the US and in the UK and will continue to do so if it suits a particular Political agenda.]

*House of Representatives
Creating a Task Force to Investigate Certain Allegations Cconcerning the Holding of Americans as Hostages by Iran in 1980
House of Representatives - February 05, 1992*: more if interested, it gets better