(Honestly Fluxx has a similar “random winner” problem as Killer Bunnies, at the best of times)

Yes. I dare say usually. Every expansion tries to fix "sudden random winner", but none of the ones I have played have solves it.

Of course, the worst Fluxx games are when one unskilled player lucks into all of the win conditions but manages to mis-play them, dragging the game out indefinitely.