Since my post about Rawicz, I've read Norman Davies' No Simple Victory, an idiosyncratic but very thought-provoking history of WWII in Europe. Davies mentions Rawicz:
Slavomir Rawicz (1915-2004) was a Polish cavalry officer who fought the Germans in 1939 but was captured by the Soviets and sentenced to twenty-five years' hard labour in a camp in eastern Siberia. He escaped with a small group of fellow inmates, and over twelve months in 1941-42, he walked the 6,500 km to Calcutta--crossing the Gobi Desert, Tibet and the Himalayas on the way. He later served with the British Eighth Army in Palestine. Several reviewers denounced his autobiographical book The Long Walk (1956) as a work of fiction, not to say fraud. But it wasn't, despite obvious embellishments. British officials in India and Afghanistan reported other similar Polish arrivals. (page 273)
Davies is a highly respected British specialist in eastern European, especially Polish, history, and his knowledge of the war is encyclopedic. His view can't be dismissed lightly. But I wish he had stated the grounds on which he believes Rawciz. (His only citation is to The Long Walk itself.) Since Rawicz lived in England from after the war until his death, it's possible that Davies and Rawicz met, and that Davies' conviction is based on a personal interview (or, conceivably, influenced by contacts with members of Rawicz's family). Since No Simple Victory is expressly an interpretive essay, not a work of narrative history, its scholarly apparatus is quite light; Davies wouldn't necessarily have disclosed such an interview in his notes.
Another factor might be Davies' emphatic belief that Soviet statements and records cannot be trusted where the Poles captured in 1939 are concerned. The Russians murdered 25,000 Polish officers and then lied about it, both crudely and creatively, until 1990. (Stalin told Churchill that all those Polish prisoners must have "escaped to China.") Their record of Rawicz's alleged release is not necessarily dispositive. Soviets were known to manufacture phony records in other embarrassing cases, e.g., in the 1960's or 1970's, after decades of denying they knew anything, they produced what they claimed was a copy of a record that Raoul Wallenberg died of a "heart attack" soon after Soviet troops arrested him in Hungary. Yeah, sure.
Finally, reading No Simple Victory you form an impression that such bizarre events (as walking from Siberia to India) were more frequent in those horrible years than is widely known. When you put several hundred million people into the blender and turn it on to whip, expected patterns of behavior get shattered and there are more chances for these improbable outliers to occur.
I'm not saying I now believe Rawicz. My initial skepticism, when I read the book many years ago, was based on my judgment of the intrinsic implausibility of a number of its claims, and that has not changed. Even Davies acknowledges that the story contains "embellishments"-- including, I assume, the face-to-face meeting with the yeti! But if Rawciz had really accomplished the basic exploit Davies credits him with--escaped and walked to India--what need would there have been for embellishment?