I was told by a client who served on a guided missle cruiser (had a designation CGN, but can't remember the name...it was named after a souther state I think) back in the late 70's early 80's. He told me that on the day of Reagan's inauguration, they moved a huge number of ships into striking distance of Iran and told Iran that they had 48 hours to release the hostages or they would be nuked (this guy said they armed the nukes and were ready to launch)...and that is why the hostages were released. Apparently, the ships were moved prior to inauguration on Reagan's directive, approved to by Carter. Don't know if this is BS or not.
The problem is that those ships didn't carry nuclear missiles capable of land attack until the mid 1980s...
Also, the hostages were being released while Reagan was being inaugurated--before he could actually give any orders.
Your friend was pulling your leg.