Syndra W + Shaco Trap

If Syndra grabs Shaco's trap before it stealths, it attacks her while she's holding it... and then it stops and doesn't vanish until a while after you drop it and it doesn't attack again, either. I'm not sure what should be happening here, but the current behavior is just weird. IMHO, it should attack immediately after being dropped, or at least this would make more sense.