I think the big problem is the fact that at least one of the US authors indicated that aircraft lost in combat were not counted as combat losses if they did not crash in the immediate vicinity of the mission or combat area. There are a number of losses which were ditched in off either coast of North Korea which were lost under suspect conditions.
The B-29 crews argue about a number of damaged aircraft written off as flak damage when the crews claimed it was "horizontal flak" from MiG cannon and not ground gunners.
Big problem is how much of this is anecdotal and how much is actual serious after-action reporting. We've gone over some of them in the past, but the problem still remains which aircraft were lost for what reasons.
One thing which IS obvious from reading the details from autobiographies of guys like Abukumov is that a lot of the claims were validated by who got to the crash site first, and in many cases it seems to be VVS pilots and not the PVO gunners. Ergo, an aircraft shot down as an F-86 is claimed due to a smoking hole in the ground, which mysteriously matches up with an F-84 shot down by flak.
But when there is R500 bonus at stake, hey, money talks...