Why are these 2 buffers joint while extracting glTF information?
The accessor (model.accessors[accessor_index]) has its own byteOffset and count values that you need to account for here.
The input and output accessors are allowed to share a bufferView, and your output is showing a dump of the same entire bufferView twice.  The first five values in that dump are the input accessor with the times (in seconds, since the start of the animation) and the remainder of the bufferView is pointed at by the output accessor.  If you account for the additional settings on the accessor itself, it should allow you to pick apart this bufferView correctly.