2.10.3

[rsl]

This is my first post... but I have been a lurker for a while.

While studying for my test (which I just submitted and luckily passed),
I came across 2.10.3:

Art. 3... If in Article 1e the error is made while the clock is running and the ball dead, it must be recognized by an official before the second live ball.

When and why would the clock be running during a dead ball?

Thanks in advance!