Sorry Brent but not true. Planes have a maximum landing weight and if they have conserved fuel (ie. flying with a tail wind) or have to divert to a closer airport they need to dump the excess fuel to get down to the specified landing weight or they could damage their landing gear
The flight to Perth WA can often have a very strong tail wind resulting in up to a 1/2 hour early arrival hence the excess fuel
.
Hope this clears things up,
Cheers,
Chris