I'll try to re-phrase:  in older NetMQ first byte (with index `Offset + i`) was LSB. When the value we want to store (length) is a multiple of 256, the LSB will be equal to 0. In this case, the check `if (m_innerBuffer[Offset + i] != 0)` will decide that value is properly (big-endian) encoded, even though it actually came from older NetMQ and is little-endian encoded.