The Summoner's Insight mastery reduces the cooldown of the 15s smite cooldown instead of the 75s charge time.
I think this is unintentional because when smite had 1 charge and a 60s cd, the mastery would reduce it to a 54s cd.
I have noticed this as well, I already opened a ticket for this issue yesterday: http://boards.na.leagueoflegends.com/en/c/bug-report/EoOtcr7x-gameplaysmites-new-stack-system-is-bugged-the-cdr-from-summoners-insight-does-not-apply
Please direct your feedback there so we can focus our responses, this way we have a better chance of getting Riot's attention and achieving a quick fix for this issue :)
