Not to be confused with a command cooldown... a teleport delay forces the player who uses /clan home to hold still for X amount of time before the teleport occurs. If the player moves (or is moved) within this allotted time the teleport is cancelled.

The reason for this delay is to counteract PVP avoidance. Players with modded clients that have hotkeys, can simple hit a key like 'H' which will execute /clan home and be instantly teleported away if they are on the losing end of a PvP battle.

added