Ekko and Galio Ignite Bug

I found a bug involving Ekko and Galio with ignite. While playing a bot game using Ekko, the enemy Galio used his ultimate on me. Right when he used his ultimate on me, however I pressed ignite on the enemy Malzahar and Ekko started running over to Malzahar outside of the Galio ultimate. So I basically was able to avoid a taunt because I used Ignite. (Imagine Ekko running to Galio to auto attack, but turning around and running out of the taunt to ignite Malzahar, then running back into Galio's ultimate).

There are similar bugs involving the summoner spells as well that I do not know if they are bugs, or if it is a mechanic, but whenever I get stunned, snared, or silenced I can still use my summoner spells (except for flash).