Lord Of War (Film) Chronology?

I watched this on BBC1 last month and picked up on something odd. At the beginning when the characters are being set up, the date is stated to be 1992. During the following moments of that whole introductory scene, Nicolas Cage's character learns that he wants to sell guns/ammo. The next date stamp we see is 1982 as we see and his brother at a gun runners convention of sorts. That is a full decade before we are initially shown the events of 1992 in which decided that he wanted to launder weaponry. It later goes on through the 80's and 90's and eventually reaches the early 00's. Have I missed something obvious or is this a truly bizarre mistake ?...