This is an assumption that may not be useful. The Buddha taught how unreliable is perception. We can see this in operation everyday. You and I could read the same passage yet perceive it differently, and in good faith paraphrase it and come out with different slants. There is a huge difference between a technical ‘translation’ and a ‘re-telling’ of something. My hypothesis is that the second ‘version’ of the talk is a re-telling rather than a translation. In principle, both have elements of unreliability built into them, but the latter is much more likely to result in something that reflects the ‘re-tellers’ perception and understanding. It can be the result of the best intentions, of wanting to clarify something that appears a bit unclear to be clearer- but then it is transformed into that persons view. This may be a totally unconscious and invisible process. Views are built on perceptions, which are unreliable. That is why the Buddha says that views are something to be abandoned, and that perception is to be seen to be unreliable. One of my favourite reported stories about Ajahn Chah is that he would have a constant ‘uncertain’ attitude towards ‘views’. Is it ‘x’ ? … uncertain, not sure…
The Buddha was so meticulous in the way he used language, with such a high order of internal consistency across his teachings. How often do we see him chastise one of the monks “foolish stupid man, when have you known me to teach it like that”… Sometimes I would find it frustrating - why say things in such a complicated and convoluted manner… 
I think this is the reason why, to reduce the possibility of wrong perception… (reduce not eliminate). The Buddha also foresaw that over time, just through the natural action of attention/perception/formation of views that his teachings on cessation would become corrupted, to something more comfortable … we even see the proto-evidence of this at the end of MN1 - and the monks were not happy…
That is why the EBTs are such a gift. One can go back with a pretty high degree of certitude, and actually read what the Buddha taught. Through the scholarship on EBTs and parallels we are closer than ever (in the last 2000 years) of having access to the actual teachings of the Buddha. This is the Standard against which everything else is measured. Reading many translations really helps, as well as referring to the parallels. And this is where I have such gratitude to Sutta Central and the work of Bhante Sujato and all the others who contribute scholarship and translations. Here we have an easily accessible tool for multiple translations and parallels. And then one can always learn Pali. Or Thai if you want to listen to and understand what Ajahn Chah was saying. There are recordings of his talks.
The Buddha said not to believe logic, or gurus, or masters, but to always compare it to his teachings and to accept it ONLY if they match. But it doesn’t stop there, it also needs to be reflected by ones own practice experience - only then can one truly come to an understanding. The rest is a pointing… the test is when it becomes a lived reality.
With regard to the issue of Nibbana and the end of the path, there is one resource that I have found that really presents this in the most thorough and skilled way, leading us through the maze of misunderstandings and through the history of misinterpretations - always coming back to the Buddhas teachings as the authority. It is the work Nibbana the Mind Stilled by Bhikkhu K Ṇānananda. It is a challenging read, 800 very dense pages. Bhikkhu Anālayo did a 3 year series on it, covering 11 chapters/sermons per year. This is probably the best way to do it - by reading the text together with listening to the lectures. Here is the link
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It is our desire that someone tell us the answer that makes us suffer, when we discover that they are fallible human beings. But this need not be the case, if one realises that these are just perspectives and experiences of individuals, and not invest anything more into it. Also one needs to be careful not to reject the whole lot, just because some aspects are limited. EG if the teacher is spot on about most things, but maybe not about cessation, it doesn’t mean that all the other teachings are worthless. Expectations cause a lot of suffering.
Just keep comparing it to what the Buddha said and to practice experience. The tricky thing is that it takes a LOT of time to become familiar with the Buddhas teachings. The more of a ‘short-cut’ we look for, the less reliable the information. There really is no short cut… just the Noble 8 fold Path and the word of the Buddha.