It was not a lie, is was misrembering the event, which had happened years earlier.
Politicians are often caught misremembering their past, in part because their lives are so well documented. Hillary Rodham Clinton’s 2008 presidential campaign was momentarily sidetracked by her own false memory of a time when, on a trip to Bosnia as first lady, she had to skip a greeting ceremony and run from her plane under sniper fire. As often happens, her memory was an embellishment of a real event, a hooked fish that got bigger in the retelling — there was fighting in the region, but not close enough to be a threat. Our memories tend to morph to match our beliefs about ourselves and our world. Mrs. Clinton did go to dangerous places, but on the tarmac in Bosnia she was met by children, not bullets
I'm sure none of you have misremembered something in your past. She was visiting a country at war. How many of you have visited a country in the midst of war? Some who were soldiers perhaps, but most people have not. She was probably in fear during that trip, and her memory played tricks on her. This kind of thing is documented all the time when people give evidence in situations of crimes, like home break-ins or street crimes they witness. The longer ago the event, the less accurate their memory is when remembering an event that was stressful and even frightening.