perfect timing rune bug

in a howling abyss custom game i bought a zhonya's hourglass before the cooldown on the stopwatch from the perfect timing rune was done.

i got the hourglass and the stopwatch didn't go away, and when the stopwatch came off of cooldown, i could use it separately from the hourglass.

i tested it a second time and it worked then too. the stopwatch and zhonyas cooldowns are separate and the broken stopwatch works to build a second hourglass 600 gold cheaper than normal. (meaning it's worth 1200 gold and a free stasis if you buy two stopwatches with this method)

never mind. apparently the first stopwatch doesn't contribute to the first zhonyas