Yi damage after death

Was attacked by master yi, he dodged Karthus ult using alpha strike, but when he died to my auto, half a second later I died to his auto attack. Does an auto after death always count as a hit or (in some of my other games) does the auto not count as a hit (thinking ranged champions). I am confused as there is some non-standard interaction going on. I would love to know the details other than it works as seen because it won't work another way (bullshit reasoning).