He also says that French Jews were deported from Drancy to Majdanek via Sobibor.
As far as I know, according to orthodoxy, the only survivors of Sobibor are those who escaped during the revolt (usually ~300). A website quoted by the Westerbork Wikipedia article describes Sobibor like this:
The clock at railway station Sobibor was a fake. The hands of the clock never moved. That, however, was not noticed by the unfortunate victims who were hurriedly forced off the train. Immediately upon arrival they were led toward the gas chambers for extermination. Only nineteen Dutch Jews escaped death from this place of horror. A timetable showing arrivals and departures was fake also. No train ever left Sobibor for another destination. The emptied trains excepted, of course. It was sent back with closed doors only to return with more victims. The thirty-four thousand three hundred and thirteen Jews who arrived here from Westerbork never noticed that this station was the end of the road for them. Not until it was too late!
Zimmerman’s Holocaust Denial book says this (see viewtopic.php?f=2&t=877):
Perhaps just as revealing as the Auschwitz deportations are the ones that took place to Sobibor. The Netherlands State Institute for War Documentation traced 19 transports of 34,313 Jews to Sobibor from March to July 1943. All of these Jews simply disappeared. Sobibor - along with Belzec, Chelmno and Treblinka - was a pure extermination camp. The only prisoners who were held in those camps were there to help dispose of murdered victims.