He sure is.

Let me add to Nick's example.

Juergen Graf writes about Sobibor:

With regards to the murder weapon, it took decades for the ruling cliques in the world to decide which one it was. One of the eyewitnesses, a Soviet Jew named Alexander Pechersky, described the mass murders as follows (9):

At first glance, as one entered, it like a normal shower: hot and cold taps for running water, wash basins... as soon as everyone was inside, the doors slammed shut with a loud noise. Out of holes in the ceiling, a heavy, blackish substance poured down in spiral shapes...

To drown out the pitiful cries of the victims, the Germans at Sobibor kept a flock of geese [!] which were made to quack (or whatever noise it is that is made by geese), very loudly, whenever the blackish substance was introduced (10).

[...]

9) Alexander Pechersky, La rivolta di Sobibor, in Yuri Suhl, Ed essi si ribellarono, Milan, 1969, p. 31.
10) ibid.

Now, what first impression does the above passage convey? That Pechersky was an eyewitness to this method of extermination. Since the method as described is obviously bogus, Pechersky must be a liar.

Read more!

I inquired Mr. Thomas (Toivi) Blatt, Sobibor survivor, about this and he replied:

Dear Mr. Romanov.
I read all of Pechersky's writing and also twice personally interviewed him. He never claims to see inside the gas chambers. Yuri Suhl book is plain literature and the author had the freedom of imagination. No Jew who was once inside the gas chamber in operation come out alive. The information about the gassing installation came from the accused Nazi testimonies in the court proceedings. Second hand stories are many times deceitful. I myself find my story completely rewritten and unrecognizable in Miriam Novich book about Sobibor.

Makes sense, doesn't it? Especially if we consider that Pechersky never was in the extermination part of the camp, Lager III.
I also wrote to Mr. Harry Mazal, owner of a great library of Holocaust books and documentation. He supplied me with the following quote from the English edition of the book (They Fought Back, edited by Yuri Suhl, 1967, Crown Publishers (New York), Library Of Congress Catalog Card No. 66-26175; emphasis mine):

On the evening of the fifth day we arrived at a small deserted station. A white sign in big gothic letters read SOBIBOR.

[...]

... Oberscharfuehrer Gomerski, a former Berlin boxer ... planted himself in front of us, scrutinized us and called out:

'Carpenters and cabinetmakers without families -- forward!'

About eighty men, most of them prisoners of war, stepped forward. I was among them. We were forced into a yard fenced off by a barbed wire. From there we were led to a barracks with barren bunks and ordered to take our places. All the others in the transport remained on the other side of the fence and we never saw them again.

[...]

A short, stocky Jew sat down near us. He was about forty years old. He had just returned from work in another yard. 'Where are you from?' he asked me in Yiddish.

[...]

The air was full of the sharp smell of something smoldering.

'What's burning there?' I asked.

'Don't look in that direction' the Jew replied, 'your comrades bodies are burning there...'

[...]

He was an old-time inmate who worked at sorting out the clothing of those who were killed. He was well informed. From him we learned where our comrades had disappeared and how the whole thing operated.

[...]

'As soon as you were separated from them, ' he said, 'they were taken to a second yard where everyone, without exception must gather. [...] ... the bareheaded women, wearing only their undergowns, and the children go first. About a hundred steps behind them go the men, completely naked. All are heavily guarded. There is the 'bath' he pointed with one hand, 'not far from where you see the smoke. Two buildings are standing there, one for women and children, the other for men. I myself have not seen what it looks like inside but people who know have described it.'

At first glance, as one entered, it like a normal shower: hot and cold taps for running water, wash basins... as soon as everyone was inside, the doors slammed shut with a loud noise. Out of holes in the ceiling, a heavy, blackish substance poured down in spiral shapes...

So what do we have here? Pechersky's description is not only hearsay, it is at least second-hand hearsay. This is crucial both for judging of Pechersky's credibility, and for the whole argument about "unreliable" Holocaust testimonies (lurid rumors and second-hand hearsay don't establish anything about eyewitnesses' credibility, as "broken phone" principle is at work - information is often distorted as it is being passed from one source to another). But Graf omitted this crucial fact, destroying any credibility he might have ever had.

Update: click here for a response to CODOH nonsense.