Tahm Kench Devour Summoner Heal gameplay bug

So me and a friend tried Tahm Kench in Coop Vs. AI tonight after trying him, and encountered a 100% reproducible bug, at least as much as we could find. This occured across two games, one with a Karthus/Tahm combo, and one with Tristana/Tahm. The bug seemed to occur whenever I, as Tahm Kench, would Devour my ally, and him ending it prematurely. This caused Summoner Heal to be set off for some reason, for both of us, giving us a fast, reliable and abusable heal. My summoner spells were Teleport and Heal, my ally's Teleport and Ignite.

Here are some pictures showing postgame for Tristana, showing 5000 healing done without a single lifesteal item or summoner heal: http://i.imgur.com/orUqLKC.png http://i.imgur.com/EIdiDdu.jpg

Here's one from Tristana's in-game, showing the Recently Healed Debuff originating from Tristana http://i.imgur.com/OT4mblK.jpg

Step by Step to reproduce:

1. Have Tahm Kench with summoner heal devour any ally
2. Have the ally prematurely exit, resulting in a summoner heal for both (This section's a little light on due to not being entirely sure how to replicate it)

Here's a video of the bug occuring, shot from Tristana's point of view. It can clearly be seen that Tristana doesn't have Summoner Heal, yet is still Healed. I, as Tahm Kench, slightly afterwards use my actual summoner heal as proof it isn't that. https://www.youtube.com/watch?v=JryaeNdsFm0

After more testing, this works with many other summoner spells, like ignite, ghost, and even Clarity, shown in the video below. Does not work with Flash or Teleport, because Tahm can't flash or teleport while someone is in his stomach https://www.youtube.com/watch?v=61hiWHvKBBA