I don't keep up with things like this (writers), but I don't suppose one of them was anti-Spike and one was pro-Spike? Maybe someone wanted to overshadow a Riley moment with a greater Spuffy moment?

Or, given the complete lack of continuity on the show, no one noticed similar words had already been said.

No one's probably pointed it out before (at least that we've seen) because Spuffy fans seem to hate As You Were, and avoid watching it. :)