[GamePlay] Anivia passive teleport bug

During a 3v3 game we encountered what we feel is an in game bug. On multiple occasions when killing Anivia she would start to cast her teleport summoner spell. We would succeed in killing her and activating her passive Rebirth. The teleport would continue to channel while in egg form and she would teleport back to a turret before we could secure the kill.

1. Start game as Anivia with Teleport summoner spell
2. Get low health in lane
3. Start casting teleport while taking damage from enemies
4. Teleport to friendly tower while in egg form

Here is a link to the match history that this occurred in: http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/1973298597/35892440