I can't speak about this from personal experience, so I have to reference what other awakened people have said. That said, it really does explain a lot. Andrew Cohen, Trungpa, Adi da, etc. etc. All seem to be people that have had significant awakenings yet have screwed up. Ken Wilber also mentions that with awakening, the "darth vader" option is always possible, its sort of like "power corrupts" in conventional life.
Of course, you could make a tautological statement that "full awakening" results in "full elimination of shadow side", but then it begs the question -- does someone have full awakening? My best guess (admittedly based on ignorance) is that full awakening is possible if conditions of experience are held constant (e.g. in a monastic situation).
But even Buddha had times when he caught "Mara" trying to corrupt him. lthough he was a monastic, he was actively involved with creating a society and navigating the power structures of the time. I'm sure if he stayed on mostly solitary retreat, he wouldn't have seen mara anymore. But because he was developing means to help other's suffering, he was innovating, and conditions of experience weren't constant. So I don't think even full awakening means there will be no more challenges to one's realization.
Ultimately it's maybe an interesting thought problem, but I guess that's all it is.
p.s. I did some googling and came across this... kinda interesting discussion of mara:
http://www.dharmalife.com/issue25/devil.html
'To me the Buddha and the devil, or Mara, are two modes of a single organism. The Buddha is the capacity of that organism to open, Mara is its capacity to shut down. And that is non-dualistic because there's only the one organism, the human being. Traditional Buddhism has succumbed to a dualism, that the Buddha is good, Mara is bad. The Buddha is perfectly good; in his idealised perfection, he is no longer quite human. Mara is this figure the Buddha overcomes. Good and evil are split off from one another in orthodox Buddhism.'