The delaying rule states that holding up the round as the last player is intentionally delaying the round for others by just waiting. An example of this is going near the end and just waiting there looking at the deaths.

The Leeching rule states that people must be trying to complete the map without waiting behind others in one place. The example i'll use is from Atomic Warfare. A runner is in stage 4 and is nearly at the end. The Leecher is staying around stage 1 waiting for them to finish.To Leech, you don't have to stay in one place. You can be running around stage 1 but it is still leeching. If that person then moves onto the next stage and the stage after that and the other runner is at the end then it is not leeching anymore as they are moving from place to place getting to the end.