ConsecutiveFrameTimeoutError for first consecutive frame #41

I found that ConsecutiveFrameTimeoutError was not raised, although, the first consecutive frame was not received after first frame and flow control exchange:
S R
-----First Frame----->
<--- Flow Control----

Is that expected behaviour - that ConsecutiveFrameTimeoutError raises only if consecutive frame receieved with delay.
What if the first consecutive frame will not come at all?
I thought in this case ConsecutiveFrameTimeoutError should be raised.