This is the first I've heard about this possibility.
During my service in Vietnam the authorization for many medals was delegated down to various unit levels (company, battalion, brigade). Only the higher valor awards were restricted to higher command authority (Silver Star, DSC, etc). We seldom saw awards ceremonies, except the occasional change-of-command with officers pinning medals on each other's chests while photographers recorded the event. Nearly all of my decorations were mailed to my "home of record" after I left Vietnam, and that was usually the first time I heard about them.
Every decoration was accompanied by copies of the orders authorizing the award and a written citation prepared by very creative young HQ staff officers (probably majored in creative writing at college). I never remembered some of those events quite the way they were described.
While processing out of active duty it was found that several awards and decorations were not recorded in my personnel files. The orders for the awards had never caught up to the HQ clerks, or they never bothered to post everything to the records. Not uncommon at all.
There were also events called "impact awards", when commanders made spot presentations in the field. Usually followed up with orders, but not always.
While in a military hospital in Japan a group of dignitaries touring the wards watched as medals were presented to us in beds and wheelchairs. After all the bigshots and photographers left they collected all the medals in a box for use at the next press event.
Still just a little bit cynical here.