I think you and the OP are agreeing with each other. The issue with a "single unreplicated paper" is exactly the issue you bring up with science as a journey. It's possible that this paper has found a genuine finding or that it is nonsense (people can find isolated published papers supporting almost anything they want even if they don't reflect the scientific consensus), but if no other researchers are even bothering to replicate the findings in it it hasn't joined the journey.