Their being killed for not *prove* that they were martyred.
One thing every dedicated anti-Catholic MUST do is remain ignorant of the lives of the saints, martyrs and non-martyrs. The lives of the saints provide prodigious evidence of the working of grace, shown by their heroism, their holiness, their miracles, their great charity.
Zola famously went to Lourdes, saying, “I will believe if I witness a miracle.” While there, he witnessed a miracle. A woman with a cancerous tumor in her face was cured. He saw her before the cure, and saw her shortly afterward, when the disfiguring tumor was gone. He turned away, and said, “To me, she is still ugly.”
The same thing happened in the gospel, when the man with the withered arm was cured. The enemies of Jesus were not converted. The same enemies witnessed Lazarus come out of the tomb after four days dead. They not only refused to believe, they plotted to kill Lazarus (as well as Jesus, of course).
When a heart is full of hate, the intellect goes dark.