Pim: "It does appear that Haeckel was convicted by a University Court of fraud."
Joseph: "That was from Pim van Meurs. Don't you believe Pim?"
Pim himself provided the answer to that question in that very same post. He said, "Btw whether or not Haeckel committed fraud, his overall findings still hold and are still quite exciting."
Since fraud is defined as a deliberate act of deception, and since it is logically impossible for someone to uncover truth while deliberately trying to deceive people, if Haeckel's findings in fact are true then he committed no fraud.
Part of the problem is that I cannot find any independent collaborating evidence that this "trial" ever took place in the manner described by the websites. That there was some sort of inquiry is not disputed, but I tend to doubt it was as grandiose as the phrase "University court" implies. For one thing, a university court has no standing in legal jurisprudence. They could have "convicted" Haeckel of premeditated murder, but they couldn't punish him and such a conviction would be illegal in any event. As such, they could never "convict" Haeckel of legal fraud even if they wanted to.
For another, the deliberate falsification of scientific data to deceive one's colleagues is a matter so serious in science that even if the court could not send Haeckel to prison it nonetheless could have stripped him of his professorship or at the very least censured him. Yet there is no record that the court punished Haeckel at all, despite his confession. That would suggest the court obviously did not consider the matter all that important, despite the claims of modern writers.
For yet another, what modern writers are carelessly calling fraud, the court would have called misconduct. Though this can mean a deliberate act to deceive, it usually means inaccuracy, carelessness or at worst (what we would now call) "fudging" the data. Haeckel's confession