[GAMEPLAY] Tibbers being immortal after being swallowed by Tahm Kench!

Just played a round of ARAM as Tahm Kench and swallowed Tibbers with my W. My team then started to burst it down to "death" within 1-2 seconds from around 1400 HP, but its life would not drop below 1 HP. It started regenerating to 3-5 HP, went back down to 1 and it started again, no matter if it got hit by a spell or a basic attack. It timed out about 7 seconds later, but had all its effects last as long as it stayed alive (burn, attacking, etc.), it was not just a visual bug.

I could not tell if there was any interaction that might have caused it aside of me swallowing it, but the only thing that crosses my mind is the fact that my swallow would have killed it with the percentage health damage. The game either counts tibbers as a unit that should not be swallowed in the first place, so it cannot be killed by the damage of Devourer, or it just cannot be executed by it.

Match history seems not to be working on the web page (at least for me), but I'll still leave the link to the match here: http://matchhistory.euw.leagueoflegends.com/en/#match-details/EUW1/2926992538/209489816

Hoping this is somehow reproduceable with the information given.

Best regards, Zensational [slayer-jinx-catface]