Bit of an ancillary deal. Since the release of BH0, one of the biggest and most contentious plot-related problems is the "B.O.W. Report" file. To sum it up, the file is referring to the Eliminator, Plague Crawler (though not quite) and Lurker B.O.W.s. Some believe that the mention of the "Progenitor Virus" means that they are created with that virus, but every single source that exists related to the game (included Darkside Chronicles) states outright that they were created with the t-Virus.
Some people usually go on to claim that "games > everything" (even though "everything" doesn't contradict the games) and say that this means that they aren't t-Creatures. However, there's actually a reason why it says Progenitor Virus. It's because "Progenitor Virus" is referring to the t-Virus, the two terms are interchangeable at times (such as in Archives, it states "he succeeded in stabilizing the Progenitor Virus", even though it is referring to the t-Virus). The t-Virus is, at its base, just a variant of the Progenitor Virus, and to the series writers, there is generally only a single "virus" (Progenitor), with several variants, mutants and derivatives. It is identifying the t-Virus as being a strain of the Progenitor Virus (which it is), rather than attempting to treat it differently as people do with Chicken Pox (you don't say it's herpes, even though it's one of the major Herpes viruses).
Simultaneously, there's another potential explanation you can use if you're unsatisfied. The t-Virus was top-secret at the time, Marcus did not want to reveal it until he created a viable B.O.W., and the report was to show failed examples of that.
Another non-existent plot hole/retcon/mistake.