Judge Hiller Zobel said in his 16-page judgment that he understood the "indescribable pain" Sunnil and Deborah Eappen, Matthew's parents, were going through, but he could not take it into account.
Mr Steven Colwell, one of the 12 jurors, immediately said he was pleased by the judge's decision. "I feel relief but I'm glad the verdict was not overturned," he said. "I can live with the fact that the sentence was reduced to manslaughter."
But he added that even had manslaughter been an option when the jury was deliberating he was not confident they would automatically have selected it instead of murder. He said several jurors had not believed Woodward's testimony.
"It still proves that she's guilty," Matthew's paternal grandmother, Mrs Achamma Eappen, said of Judge Hiller Zobel's decision.
"I guess the judge knows what he's doing and as long as she pays for what she has done to baby Matthew," she said from her home in Hinsdale, Illinois. "All that we wanted was for us to know what has really happened and this still shows that she's guilty."
The Eappens themselves were not in court. A friend said they had been forced to leave their home in Newton, Cambridge, where Woodward worked for 11 weeks as their au pair, after receiving dozens of death threats and hate-mail, from both Britain and the United States.
"They feel it's shameful they way they've been treated, they feel terrible. They've done nothing except lose their child yet somehow everyone's venting against them," said the friend of the baby's parents, who did not wish to be named for fear of reprisals.
The prosecution at the trial argued Woodward hated her job because it interfered with her social life and said she acted out of malice because the Eappens had tried to impose a curfew.