Clearly it's longer, but I don't think that was his point. As sbm pointed out, it's completely arbitrary to decide what identifiers deserve to be "shortened by 8 bytes". Functionality, expressiveness, readability and convenience are not calculated solely on an inverse relationship of # bytes.
Practically speaking, I can't imagine $nick(#,*).random would really be used enough to justify that. I know people write random nick popups, but they usually just write a handful-- picking a random nick is not really a core function that everyone needs to perform on a daily basis-- and for the few that actually do, it's scriptable.
From an organizational/cohesion
standpoint, a ".random" property has no place in an identifier that's meant to access a nick list. That just makes things really messy. How data in a list based identifier is accessed should not be the concern of the identifier.