Labour sources later tried to claim that the party's literature had used the "commonly understood academic timetable" of when the Shoah took place.
They accepted that others saw the rise to power of Hitler in 1933 as the real beginning of the Holocaust.
The Kristallnacht pogrom against Jews, which left at least 91 dead, took place in November 1938.
Ms Smeeth said she had been left incensed by Mr Corbyn's failure to answer the questions she had put to him at the meeting.
She raised the case of former Labour staffer Sam Matthews who had received a death threat from a pro-Corbyn activist after he appeared as a whistleblower on the BBC Panorama episode about Labour's racism crisis.
"Sam got a death threat and had to spend three hours with the Met Police on a Saturday night," she said.
"It went in one ear and out another," she said of Mr Corbyn's response. "I don't understand where humanity is meant to exist in our party if this is where we are.
"I read out a list of everything that had happened, not in the past three years, but in the past month.
"No comment, no reference, no awareness."
Earlier Labour had attempted to bolster muted response to an announcement, made on Monday ahead of a Shadow Cabinet meeting on the crisis, to move to allow the General Secretary, in company with the party's governing body, the National Executive Committee (NEC), to expel antisemites.
A later statement by the Shadow Cabinet announced further use of independent legal advice on decisions. It is understood deputy leader Tom Watson had left the meeting when this was issued.
But sources said he was encouraged by the announcement that independent advisers were being considered.
But it was unclear how the proposal, which is to be voted on at Tuesday's NEC meeting, would work.
Leaving the weekly PLP meeting, one MP said: "Same sh*t, different day."
Another said Mr Corbyn sounded like a "broken record".
But one Labour source said they believed their had been "some movement" with the Shadow Cabinet announcement.
Labour General Secretary Jennie Formby, who has recently been undergoing chemotherapy, addressed the PLP meeting at the start and was warmly applauded.
She had to be helped as she left by Mr Corbyn's Chief of Staff Karie Murphy.
