It is a hard call to say which way this issue lands. Obviously Medium will not tell us exactly how they are capturing a read, because if they did it would provide the ability for people to cheat the system more easily.
However, at the same time, we don’t know if it is something we are doing that is causing the read not to be calculated.
At this point, I just accept the stats as they come. I know at times I get more responses then reads on some smaller stories. I know that I can get read time recorded despite getting no reads recorded.