Are we talking about claims or kills?
In general, I doubt that the US/UK/RCAAF/SU loss lists are correct and avaiable to verify the claims. Even if losses match (esspecially US, since these are accessable, god thanks!) claims, they are often connected to other reasons than damage inflyted by Me-262 (the same was done in Korea: engine failure, midaircollision, plane running out of fuel and so on instead of the MiGs, which inflicted the damage..).
Sorry to quote ancient post, but interesting thread and I wasn't around
The partisans of Soviet claims in Korea, *claim* the US extensively faked the causes of its losses in Korea. because they are embarassed by the very high overclaim ratio of the "their" guys. They are aided by some off hand, non quantified statements in old US books implying this was true. And then they have repeated it so many times (especially on the internet in recent years) to make it a "factoid".
But I've looked into it in detail in the US records v Soviet claims, and it's just not true. The overwhelming majority of Soviet claims correspond to combats recorded at the same time and place in USAF records, between the same general types of planes (swept wing jet, straignt wing jet, prop) the Soviets say. It's just the results that differ, in the then-secret level documents of both sides. When other US losses occured the same days for non-MiG causes (still not anywhere near enough to justify the Soviet claims), that's usually well documented to have happened in different circumstances, different place and time. Again, in voluminous then-secret records of many kinds, all bascially consistent. At the margin there was a tendency to class loss cause "unknown" without certainty it was MiG; a few planes returning safely but not repaired were not counted (*not* common, and should they even count?) and in a few cases a pilot might have claimed mechanical failure when really hit, but it was not systematic or statistically signficant.
It's not totally off topic because people often use unproven (or untrue) statements about one war to refer to another; if the statement is followed up, oh wait that's off topic.... I don't know the exact nature of USAAF WWII records, but using the false claim about Korea undercuts the statement that losses to Me-262's were understated, since it was not true in Korea to the extent of explaining any significant part of the MiG's overclaiming.
Going the other way I didn't see mentioned on the thread Foreman and Harvey's "Me-262 Combat Diary". Not a new book, it compared claims and losses pistons v. 262's and shows the USAAF claims against jets (RAF's too) to have been quite accurate, 262 losses to pistons something like 75% of the Allied official *fighter* credits for Me-262's destroyed (always key distinction: fighter and bomber claims); what I got counting up incidents in that book. Very few piston fighters can be documented to have been downed by 262's; perhaps with more research some more would turn up, but the 262 claims v piston fighters were clearly highly overstated, their claims v. bombers more reasonable. Moreover discussions of particular incidents in books like Smith and Creek generally follow Foreman, I don't know of anyone disproving the general pattern of claim/loss accounting in that book.
The piston fighters had "unfair" advantages v. the German gets (numbers and fuel persistence to hang around 262 bases and get the jets coming and going), but air combat is never about "fair".
Joe