Fickle means changing frequently especially as regards to one’s loyalties or affections
He began to cry because some one scared him
Given the environment malvolio was in, as an adult he still should be responsible for his actions. His intent towards olivia was never out of love but more of a struggle for social power. Although the fact that he was put to disgrace being treated like a madman for the sake of entertainment of other is not acceptable not even on today's society.
This is why he was found guilty
