[GAMEPLAY] Tahm Kench R bug that kept me inside him until he died then i just "appeared"

as you can see from the video (https://www.youtube.com/watch?v=lOgo6eHwLlY&feature=youtu.be) that i went to baron bit with tahm and well he just kept me insdie until he died then i appeared. havent ever seen this before. havent tried to repeat it but yea