Is this buff transfer a bug or did it just time out?

Hello, so I killed this shaco and you can clearly see his buff timer. It didn't look like it was running out anytime soon, it was more than halfway done. After I killed him I see the buff flying to me but I didn't get it. Did it just time out, was it because I was coming out of my invisibility or is it just a bug? http://plays.tv/video/59ed49e4ef5140eef7/bug-