There are so many things to take into account.
Like dispersion... "I lit you up" - hits were spread across the airframe with no single point of concentration
Or guns... "I lit you up with 20mm" - or 303? Dual calibre setups have quite different ballistics. So hits maybe 303 (or .50) with the 20mm dropping under
Or convergence... "I lit you up with 6 50's" - no you hit me with 3 or 2 and the rest missed me. Don't assume that because you hit me with 1 gun all 6 got me. Often exaggerated when shooting at small aircraft inside or outside convergence (there are some jug pilots, particularly the 56th guys, who absolutely nail they convergence - and when they do it shreds you)
...and some days you just have a sucky day.