Got hit by a nid spear while my sivir spell shield was up

A nid threw a max range spear that I decided to take to get some extra mana back. Instead of getting mana back and negating the damage the spear instead did full damage to me. I know that the spell shield did not time out because I just activated it and it disappeared as soon as the spear hit.

Thankfully I was just taking that spear for the hell of it so no real harm was done but if this happened in an actual game it could be exploited. Fix this please.

Also sometimes her spear still goes invisible.