3 weapon glitch (Pillar of Autumn)

Welcome to my site once again and i bring you the famous tri-weapon glitch...
Well after Captain Keyes hands you the unloaded pistol you run out to the area where there is Grunts.If you do it normally, it will show "Checkpoint done" and the grunts will appear and your pistol will appear. You are supposed NOT get the pistol and grunts. The trick is when you are getting out of the cockpit, try to get out ASAP and not bump into anything. It may be difficult at first but you have to get out REAL FAST to miss the "Checkpoint done".If you manage to not get your pistol but your assault rifle, get a plasma rifle. After that return to Captain Keyes and there you go! You get the pistol you missed , with a assualt rifle and a plasma rifle.Tri-Weapon!