Those who remembered the words of the Buddha, those who wrote them down, and those who translated them were not all Buddhas. There will be errors, omissions and additions.
You may encounter fundamentalists in Buddhism as in Christianity who believe that what they read is totally valid because it is what the Buddha actually taught.
Others will limit that to the teachings ascribed to Shakyamuni and reject the Mahayana and Vajrayana.
In short, errors are pretty much a certainty.
However, you will encounter much argument about terminology on the web. From my perspective I see Theravadans describe the Mahayana and Vajrayana as 'superstition', and also seen Mahayana and Vajrayana followers call Theravada a 'HInayana' practice, and claim it to be inferior.
Briefly, nobody knows. Examine the sources you have available and engage in practice based upon what seems correct and you will discover if it works for you. I'm not a fan of 'one size fits all' and feel sorry for those who struggle for decades with an approach which really does not suit them, frustrated at the progress of their companions. I also lay part of the blame at the feet of gurus who believe that what worked for them must be 'the way' for someone else - the fact is that they may not know of any alternative.