All writings (including my own) of cause has some bias to it. See if you can spot any bias in this quote from Tacitus in his Annuals 15.44:
Consequently, to get rid of the report, Nero fastened the guilt and inflicted the most exquisite tortures on a class hated for their abominations, called Christians by the populace. Christus, from whom the name had its origin, suffered the extreme penalty during the reign of Tiberius at the hands of one of our procurators, Pontius Pilatus, and a most mischievous superstition, thus checked for the moment, again broke out not only in Judæa, the first source of the evil, but even in Rome, where all things hideous and shameful from every part of the world find their entre and become popular.
Given the fact that he calls this Christianity a source of abomination and evil, it is very unlikely that it was doctored by a Christian scribe at a latter date.
Pontius Pilate Position: Procurator or Prefect?
There is a small debate in this text about what Tacitus says about Pilate's position, but even the atheist historian Richard Carrier (who is the only historian I know of who says: "[it is] very probable Jesus never actually existed") doesn't even have a problem with this so called error:
It seems evident from all the source material available that the post was always a prefecture, and also a procuratorship. Pilate was almost certainly holding both posts simultaneously, a practice that was likely established from the start when Judaea was annexed in 6 A.D. And since it is more insulting (to an elitist like Tacitus and his readers) to be a procurator, and even more insulting to be executed by one, it is likely Tacitus chose that office out of his well-known sense of malicious wit. Tacitus was also a routine employer of variatio, deliberately seeking nonstandard ways of saying things (it is one of several markers of Tacitean style). So there is nothing unusual about his choice here. - From point 10. i. on this page