How to count the bits with a 1 bit error correction Hamming code?
Yes, it is about what bit-endianness you choose. Just make sure you are using the same interpretation on both ends.

(However if on 'Endian ordering' you meant byte order, that does not really apply here. As most Hamming codes do not transfer a whole number of data bytes, it is far simpler to think about the input as a stream of bits)